Performance Awards - Additional Information (Detail) - Performance Awards $ in Millions	12 Months Ended
Dec. 31, 2016 USD ($)
2014 EIP
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Performance period	3 years
November 2013
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Payments	$ 0.3

Amount of cash paid related to share-based compensation liabilities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration