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Common Stock - Additional Information (Detail) (USD $)
 12 Months Ended 0 Months Ended 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Sep. 16, 2010
Sep. 14, 2010
Dec. 31, 2013
Westbury Agreement [Member]
Sep. 14, 2010
Westbury Agreement [Member]
Aug. 30, 2013
MMP [Member]
Aug. 30, 2013
MMP [Member]
Westbury Agreement [Member]
Jul. 02, 2013
MMP [Member]
Westbury Agreement [Member]
Dec. 31, 2013
Maximum [Member]
Dec. 31, 2013
2006 Notes [Member]
Jun. 30, 2011
2006 Notes [Member]
Sep. 30, 2010
2006 Notes [Member]
Schedule Of Common Stock [Line Items]                            
Common stock, shares authorized 250,000,000 250,000,000                        
Common stock, par value $ 0.01 $ 0.01       $ 7.25 $ 6.25              
Common stock voting rights One vote for each share held on all matters submitted to a vote of stockholders. There are no cumulative voting rights with respect to the election of directors.                          
Registration statement declaration date                       Aug. 04, 2006    
Convertible notes retired                         $ 39,300,000 $ 60,000,000
Remaining convertible notes                       750,000    
Senior leverage ratio                     2.0      
Stock repurchase program authorized to be repurchased 0.0 1,000,000.0 1,000,000.0 4,578,894 7,716,669   7,700,000   3,850,000          
Stock repurchase program cost 397,548,000 371,080,000   25,100,000 48,500,000                  
Percentage of Holding               50.00% 50.00%          
Common stock, per share amount               $ 6.65 $ 6.65          
Payment for acquisition of treasury stock $ 26,468,000 $ 5,716,000 $ 9,513,000         $ 25,700,000 $ 25,700,000          
Number of days moving average share price calculation                 60 days 60 days