General - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2018	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Derivative effective dates	Aug. 12, 2015
Sales returns reserve	$ 30.7	$ 43.4

Amount of estimated sales returns.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84158767&loc=d3e18780-107790

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 15
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=68051624&loc=d3e47468-111626

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Balance Type:	credit
Period Type:	duration