Stock-based Compensation and Outstanding Awards - Summary of Status of the Nonvested Shares (Parenthetical) (Detail)	9 Months Ended
Sep. 30, 2015 shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares paid for tax withholding	63,209

For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer.

No definition available.

Name:	us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration