XML 164 R126.htm IDEA: XBRL DOCUMENT v2.4.0.6
Stockholders' Equity - Summary of Changes in Common Shares Available for Awards under 2005 Contingent Stock Plan (Detail) (USD $)
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares withheld for taxes 524,910 457,902 53,393
Number of shares available, end of year 6,426,953 7,909,064 4,997,297
Restricted Stock SLO Awards [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock shares awarded (135,343) (24,515) (12,895)
2005 Contingent Stock Plan [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares available, beginning of year 7,909,064 4,997,297 5,578,005
Weighted average per share market value of awards on grant date 17.19 24.93 21.46
2005 Contingent Stock Plan [Member] | Restricted Stock [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Additional restricted stock shares available due to 2011 amendment to the 2005 Contingent Stock Plan   4,000,000  
Restricted stock shares awarded (703,620) (308,650) (403,360)
Restricted stock shares forfeited 41,700 41,400 19,133
2005 Contingent Stock Plan [Member] | Restricted Stock Units (RSUs) [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock shares awarded (191,700) (133,650) (115,150)
Restricted stock shares forfeited 12,200 3,500 12,500
2005 Contingent Stock Plan [Member] | Restricted Stock SLO Awards [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock shares awarded (3,788) (6,080) (12,895)
2005 Contingent Stock Plan [Member] | Restricted Stock Units RSU SLO Awards [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock shares awarded (6,795) (28,516) (134,329)
2009 Two-year PSU Awards [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock shares awarded   (1,114,139)  
2009 Three-year PSU Awards [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock shares awarded (1,155,018)