v2.4.0.6
Equity and Earnings Per Share Basic Table (Detail) (USD $)
In Thousands, except Share data, unless otherwise specified
 3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Basic earnings per share:    
Net income attributable to common stockholders $ 6,557 $ 11,084
Add (deduct) net income attributable to non-fair value redemption rights 0 1,239
Net income available for common stockholders $ 6,557 $ 12,323
Weighted average shares of common stock outstanding:    
Basic 47,499,898 45,576,925
Basic earnings per share $ 0.14 $ 0.27
Common Class A
    
Weighted average shares of common stock outstanding:    
Basic 47,499,798 45,576,825
Common Class B
    
Weighted average shares of common stock outstanding:    
Basic 100 100