Leases - Operating Leases Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Operating Leases Information [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 26.2
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 9.0
Weighted-average remaining lease term	7 years 3 months 18 days
Weighted-average discount rate applied to operating leases	3.60%