Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions		12 Months Ended
	Feb. 18, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]
Operating lease obligation expiration period		2022
Rental expense for operating leases		$ 13.3	$ 13.3	$ 12.9
Sublease income		0.9	$ 0.8	$ 0.7
Estimated total costs to remediate property	$ 8.3
Accrual for reasonably estimable remediation cost increased		$ 8.0