Marketable Securities and Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended
	Jul. 31, 2014	Jul. 31, 2017	Jun. 30, 2017	Mar. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate carrying amount of other investments			$ 7.6	$ 7.2
Subsequent Event
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate carrying amount of other investments		$ 6.0
ECP Entwicklungsgesellschaft mbH
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments to acquire businesses, cash paid	$ 13.0
Potential payouts payments	$ 15.0