| Restricted Stock Unit Outstanding (Detail) (Restricted Stock Units (RSUs)) | 12 Months Ended | |||
|---|---|---|---|---|
| Dec. 31, 2013 | ||||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
| Awards expected to vest by period | 1,331,753 | |||
| 2014 | Restricted Stock Units subject to service requirements | ||||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
| Awards expected to vest by period | 359,785 | |||
| 2014 | Restricted Stock Units subject to service and other requirements | ||||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
| Awards expected to vest by period | 67,877 | [1] | ||
| 2015 | Restricted Stock Units subject to service requirements | ||||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
| Awards expected to vest by period | 719,971 | |||
| 2015 | Restricted Stock Units subject to service and other requirements | ||||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
| Awards expected to vest by period | 184,120 | [1] | ||
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- Definition Share based compensation arrangement by share based payment award equity instruments other than options vested and expected to vest number. No definition available. 
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