Schedule of Components of Lease Expense (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Finance lease cost
Amortization of right-of-use assets	$ 0.9
Interest on lease liabilities	0.1
Operating lease cost	16.9
Short-term lease cost	0.7
Variable lease cost	1.8
Total lease cost	$ 20.4