Annual report pursuant to Section 13 and 15(d)

Equity Structure and Transactions - Additional Information (Detail)

v2.4.0.8
Equity Structure and Transactions - Additional Information (Detail) (USD $)
In Thousands, except Share data, unless otherwise specified
 12 Months Ended 1 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2013
Common Stock, Regular
Dec. 31, 2012
Common Stock, Regular
Dec. 31, 2011
Common Stock, Regular
Dec. 31, 2013
Common Stock, Special
Dec. 31, 2012
Common Stock, Special
Dec. 31, 2011
Common Stock, Special
Mar. 06, 2014
Subsequent Event
Equity Structure And Transactions [Line Items]                    
Preferred stock, shares authorized 20,000,000 20,000,000                
Preferred stock, par value $ 0.00001 $ 0.00001                
Paid cash dividends, per share       $ 0.36 $ 0.32 $ 0.16 $ 0.42 $ 0.79 $ 0.63  
Cash dividends paid $ 58,846 $ 82,832 $ 58,756       $ 31,800 $ 59,000 $ 46,900  
Dividends declared, per common share                   $ 0.10
Dividend payable date                   Mar. 31, 2014
Dividend record date                   Mar. 18, 2014