Income Taxes - Reconciliation of Federal Statutory Income Tax Rate to Effective Tax Rate (Detail)		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal statutory income tax rate		19.00%	19.00%	19.30%
Tax effect of international operations	[1]	(8.20%)	(9.90%)	(18.70%)
Change in valuation allowances		1.10%	7.90%	27.60%
Excess tax benefits on stock-based compensation		(0.70%)	(1.70%)	(4.50%)
Tax effect of U.S. tax reform		0.00%	(0.90%)	1.30%
Tax effect of early extinguishment of debt		0.00%	0.90%	9.00%
Effective tax rate		11.20%	15.30%	34.00%

[1] ⁽¹⁾  The tax effect of international operations consists of non-U.K. jurisdictions.