Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation and Cash-Based Incentive Compensation (Schedule of Stock Activity Related to Share-Based Compensation) (Detail)

v2.4.0.6
Share-Based Compensation and Cash-Based Incentive Compensation (Schedule of Stock Activity Related to Share-Based Compensation) (Detail) (USD $)
 6 Months Ended 12 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2012
Minimum
Jun. 30, 2012
Maximum
Dec. 31, 2014
Subsequent Event
Jul. 31, 2015
Subsequent Event
Restricted Stock
Dec. 31, 2014
Subsequent Event
Restricted Stock
Dec. 31, 2013
Subsequent Event
Restricted Stock
Dec. 31, 2012
Subsequent Event
Restricted Stock
Dec. 31, 2014
Subsequent Event
Restricted Stock Units (RSUs)
Dec. 31, 2013
Subsequent Event
Restricted Stock Units (RSUs)
Dec. 31, 2012
Subsequent Event
Restricted Stock Units (RSUs)
Jun. 30, 2012
Restricted Stock
Jun. 30, 2012
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                          
Shares, Outstanding 1,732,703                     51,870  
Shares, Granted 757,699 [1]                     21,954  
Shares, Vested                       (27,475)  
Shares, Forfeited (36,543)                        
Shares, Outstanding 2,453,859 [2]                     46,349 [3]  
Weighted Average Grant Date Fair Value Per Share, Outstanding                       $ 15.81 $ 14.67
Weighted Average Grant Date Fair Value Per Share, Granted                       $ 19.13 $ 18.64 [1]
Weighted Average Grant Date Fair Value Per Share, Vested                       $ 13.59  
Weighted Average Grant Date Fair Value Per Share, Forfeited                         $ 24.38
Weighted Average Grant Date Fair Value Per Share, Outstanding                       $ 18.70 [3] $ 15.75 [2]
Awards expected to vest by period         7,314 12,354 24,019 2,662 751,765 496,339 1,205,755    
Range of Restricted stock units   0 871,354                    
Restricted stock units expected to increase       871,354                  
[1] Grants for the 2012 RSUs are subject to adjustment once the specified performance requirements can be measured. As of June 30, 2012, none of the performance targets for the 2012 RSUs are measurable as the earnings per share and the TSR for 2012 components are measured as of December 31, 2012. Subject to the performance against specified targets, the range of 2012 RSUs that may ultimately be issued is zero to 871,354 RSUs as of June 30, 2012.
[2] Subject to the satisfaction of service conditions, 1,205,755 and 496,339 RSUs will vest in 2012 and 2013, respectively. Subject to the satisfaction of performance and service conditions, 751,765 RSUs will vest in 2014, which may be increased up to 871,354 RSUs depending on the specified performance results.
[3] Subject to the satisfaction of service conditions, 2,662 shares, 24,019 shares, 12,354 shares and 7,314 shares will vest in 2012, 2013, 2014 and 2015, respectively.