Stock-Based Compensation - Employee Withholding Taxes on Stock Awards - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015
Employee Withholding Taxes on Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payment of withholding taxes related to stock awards	$ 0.2	$ 0.4

Amount of cash outflow to satisfy an employee's income tax withholding obligation as part of a net-share settlement of a share-based award.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3291-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration