Stock-Based Compensation - Summary of RSUs/Restricted Stock Granted under Award Plan (Detail) - shares |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Restricted Stock and RSUs, Granted | 1,377,263 | ||
| RSUs/Restricted Stock [Member] | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Awards to employees cliff vesting | 303,999 | 287,963 | 370,812 |
| Annual Incentive Compensation [Member] | RSUs/Restricted Stock [Member] | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Restricted Stock and RSUs, Granted | 952,329 | 1,022,295 | 1,172,381 |
| Annual Rsus Granted | RSUs/Restricted Stock [Member] | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Restricted Stock and RSUs, Granted | 1,256,328 | 1,310,258 | 1,543,193 |