Quarterly report pursuant to Section 13 or 15(d)

Supplemental Guarantor Information (Condensed Consolidating Balance Sheet) (Detail)

v2.4.0.6
Supplemental Guarantor Information (Condensed Consolidating Balance Sheet) (Detail) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2012
Dec. 31, 2011
Sep. 30, 2011
Dec. 31, 2010
Current assets:        
Cash and cash equivalents $ 6,993 $ 4,512 $ 7,666 $ 28,655
Receivables:        
Oil and natural gas sales 68,230 98,550    
Joint interest and other 21,105 25,804    
Income taxes 14,284      
Total receivables 103,619 124,354    
Restricted cash and cash equivalents 24,026      
Deferred income taxes - current   2,007    
Deposit for acquisition 22,800      
Prepaid expenses and other assets 32,455 30,315    
Total current assets 189,893 161,188    
Property and equipment - at cost:        
Oil and natural gas properties and equipment 6,229,626 5,959,016    
Furniture, fixtures and other 20,912 19,500    
Total property and equipment 6,250,538 5,978,516    
Less accumulated depreciation, depletion and amortization 4,556,548 4,320,410    
Net property and equipment 1,693,990 1,658,106    
Restricted deposits for asset retirement obligations 28,441 33,462    
Other assets 14,328 16,169    
Total assets 1,926,652 1,868,925    
Current liabilities:        
Accounts payable 104,274 75,871    
Undistributed oil and natural gas proceeds 34,660 33,732    
Asset retirement obligations 83,545 138,185    
Accrued liabilities 32,331 29,705    
Income taxes 350 10,392    
Deferred income taxes - current 2,945      
Total current liabilities 258,105 287,885    
Long-term debt 719,000 717,000    
Asset retirement obligations, less current portion 250,704 255,695    
Deferred income taxes 98,393 58,881    
Other liabilities 9,470 4,890    
Shareholders' equity:        
Common stock 1 1    
Additional paid-in capital 396,601 386,920    
Retained earnings 218,545 181,820    
Treasury stock, at cost (24,167) (24,167)    
Total shareholders' equity 590,980 544,574    
Total liabilities and shareholders' equity 1,926,652 1,868,925    
Parent Company [Member]
        
Current assets:        
Cash and cash equivalents 6,993 4,512 7,666 28,655
Receivables:        
Oil and natural gas sales 53,969 78,131    
Joint interest and other 21,105 25,804    
Income taxes 124,012 74,183    
Total receivables 199,086 178,118    
Restricted cash and cash equivalents 24,026      
Deferred income taxes - current   2,007    
Deposit for acquisition 22,800      
Prepaid expenses and other assets 32,455 30,315    
Total current assets 285,360 214,952    
Property and equipment - at cost:        
Oil and natural gas properties and equipment 5,917,591 5,689,535    
Furniture, fixtures and other 20,912 19,500    
Total property and equipment 5,938,503 5,709,035    
Less accumulated depreciation, depletion and amortization 4,384,839 4,208,825    
Net property and equipment 1,553,664 1,500,210    
Restricted deposits for asset retirement obligations 28,441 33,462    
Other assets 421,125 372,572    
Total assets 2,288,590 2,121,196    
Current liabilities:        
Accounts payable 103,370 73,333    
Undistributed oil and natural gas proceeds 34,437 33,391    
Asset retirement obligations 83,545 138,185    
Accrued liabilities 32,331 29,705    
Deferred income taxes - current 2,945      
Total current liabilities 256,628 274,614    
Long-term debt 719,000 717,000    
Asset retirement obligations, less current portion 221,478 228,419    
Deferred income taxes 114,379 76,518    
Other liabilities 386,125 280,071    
Shareholders' equity:        
Common stock 1 1    
Additional paid-in capital 396,601 386,920    
Retained earnings 218,545 181,820    
Treasury stock, at cost (24,167) (24,167)    
Total shareholders' equity 590,980 544,574    
Total liabilities and shareholders' equity 2,288,590 2,121,196    
Guarantor Subsidiaries [Member]
        
Receivables:        
Oil and natural gas sales 14,261 20,419    
Total receivables 14,261 20,419    
Total current assets 14,261 20,419    
Property and equipment - at cost:        
Oil and natural gas properties and equipment 312,035 269,481    
Total property and equipment 312,035 269,481    
Less accumulated depreciation, depletion and amortization 171,709 111,585    
Net property and equipment 140,326 157,896    
Deferred income taxes 15,986 17,637    
Other assets 376,655 275,181    
Total assets 547,228 471,133    
Current liabilities:        
Accounts payable 904 2,538    
Undistributed oil and natural gas proceeds 223 341    
Income taxes 110,078 84,575    
Total current liabilities 111,205 87,454    
Asset retirement obligations, less current portion 29,226 27,276    
Shareholders' equity:        
Additional paid-in capital 231,759 231,759    
Retained earnings 175,038 124,644    
Total shareholders' equity 406,797 356,403    
Total liabilities and shareholders' equity 547,228 471,133    
Eliminations [Member]
        
Receivables:        
Income taxes (109,728) (74,183)    
Total receivables (109,728) (74,183)    
Total current assets (109,728) (74,183)    
Property and equipment - at cost:        
Deferred income taxes (15,986) (17,637)    
Other assets (783,452) (631,584)    
Total assets (909,166) (723,404)    
Current liabilities:        
Income taxes (109,728) (74,183)    
Total current liabilities (109,728) (74,183)    
Deferred income taxes (15,986) (17,637)    
Other liabilities (376,655) (275,181)    
Shareholders' equity:        
Additional paid-in capital (231,759) (231,759)    
Retained earnings (175,038) (124,644)    
Total shareholders' equity (406,797) (356,403)    
Total liabilities and shareholders' equity $ (909,166) $ (723,404)