Basis of Presentation and Principles of Consolidation - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2017 Segment	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement or change in accounting principle, effect of adoption, quantification			$ 0.0
Number of reportable segments | Segment	3
Operating leases, future minimum payments			7.5
Additional Paid-in Capital [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement or change in accounting principle, effect of adoption, quantification			0.5
Retained Earnings (Accumulated Deficit) [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement or change in accounting principle, effect of adoption, quantification			(0.5)
Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by (used in) operating activities		$ 0.6
Net cash provided by (used in) financing activities		$ (0.6)
Accounting Standards Update 2016-09 | Additional Paid-in Capital [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement or change in accounting principle, effect of adoption, quantification			0.5
Accounting Standards Update 2016-09 | Retained Earnings (Accumulated Deficit) [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement or change in accounting principle, effect of adoption, quantification			$ (0.5)