Quarterly report pursuant to Section 13 or 15(d)

Acquisitions and Divestitures - Business Acquisition Pro Forma Information Incremental Items (Parenthetical) (Details)

v3.3.0.814
Acquisitions and Divestitures - Business Acquisition Pro Forma Information Incremental Items (Parenthetical) (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Business Acquisition [Line Items]      
Long-term debt, less current maturities $ 1,426,437   $ 1,360,057
Federal statutory income tax rate 35.00% 35.00%  
Woodside Properties      
Business Acquisition [Line Items]      
Long-term debt, less current maturities   $ 54,800  
Effective interest rate   1.80%  
Federal statutory income tax rate   35.00%