Consolidated Statements of Equity (USD $)
In Thousands, except Share data, unless otherwise specified
Total
Common Stock
Additional Paid-in Capital
Retained Earnings
Accumulated Other Comprehensive Income
Noncontrolling Interest
Beginning balance, amount at Dec. 31, 2012 $ 4,609,861 $ 4,180,778 $ 73,530 $ 354,991 $ (2,191) $ 2,753
Beginning balance, shares at Dec. 31, 2012   205,399,102        
Activities during the period (unaudited) [Roll Forward]            
Net income 127,939     114,826   13,113
Exercise of stock options, shares   280,366        
Exercise of stock options, amount 1,928 2,753 (825)      
Vesting of restricted stock units, shares   451,404        
Vesting of restricted stock units, amount 0 24,697 (24,697)      
Tax benefit on options exercised 9,479   9,479      
Stock-based compensation 13,131   13,131      
Distributions to non-controlling interest (10,115)         (10,115)
Other comprehensive income, net of tax 1,047       1,047  
Ending balance, amount at Jun. 30, 2013 4,753,270 4,208,228 70,618 469,817 (1,144) 5,751
Ending balance, shares at Jun. 30, 2013   206,130,872        
Beginning balance, amount at Dec. 31, 2013 4,911,498 4,215,291 77,790 617,161 (1,752) 3,008
Beginning balance, shares at Dec. 31, 2013 206,305,070 206,305,070        
Activities during the period (unaudited) [Roll Forward]            
Net income 163,586     134,877   28,709
Exercise of stock options, shares   262,204        
Exercise of stock options, amount 4,944 7,026 (2,082)      
Exercise of warrants, shares   425,160        
Exercise of warrants, amount 3,453 20,624 (17,171)      
Vesting of restricted stock units, shares   418,931        
Vesting of restricted stock units, amount 0 18,726 (18,726)      
Tax benefit on options exercised 3,993   3,993      
Stock-based compensation 15,398   15,398      
Distributions to non-controlling interest (25,800)         (25,800)
Other comprehensive income, net of tax (82)       (82)  
Other (321)   (321)      
Ending balance, amount at Jun. 30, 2014 $ 5,076,669 $ 4,261,667 $ 58,881 $ 752,038 $ (1,834) $ 5,917
Ending balance, shares at Jun. 30, 2014 207,411,365 207,411,365