Stockholders' Equity - Summary of Stock Appreciation Rights Activity (Parenthetical) (Detail)	Dec. 31, 2015 $ / shares
Equity Incentive Plan [Member] \| Stock appreciation rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing stock price of common stock	$ 48.34

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration