Income Taxes - Attributes Available for Utilization (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
U.S. federal net operating losses
Operating Loss Carryforwards [Line Items]
Attribute amount	$ 2.9
Deferred Tax Asset Attributes, First Year of Expiration	Dec. 31, 2037
U.S. state net operating losses
Operating Loss Carryforwards [Line Items]
Attribute amount	$ 915.7
Deferred Tax Asset Attributes, First Year of Expiration	Dec. 31, 2021
U.S. federal tax credits
Operating Loss Carryforwards [Line Items]
Attribute amount	$ 2.0
Deferred Tax Asset Attributes, First Year of Expiration	Dec. 31, 2029
U.S. state tax credits
Operating Loss Carryforwards [Line Items]
Attribute amount	$ 1.4
Deferred Tax Asset Attributes, First Year of Expiration	Dec. 31, 2027
Foreign net operating losses(a)
Operating Loss Carryforwards [Line Items]
Attribute amount	$ 332.1	[1]
Deferred Tax Asset Attributes, First Year of Expiration	Dec. 31, 2021

[1] (a) Includes approximately $224.9 of net operating loss carryforwards in Luxembourg as of December 31, 2020.