Income Taxes - Reconciliation of Federal Statutory Income Tax Rate to Effective Tax Rate (Detail)		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Federal statutory income tax rate	[1]	20.00%	20.30%	21.00%
Tax effect of international operations		(11.80%)	(6.50%)	(4.90%)
Change in valuation allowances		9.70%	6.90%	4.40%
Withholding taxes		0.90%	0.60%	2.80%
Interest limitations		0.60%	0.70%	1.00%
Non-deductible transaction costs		0.10%	0.50%	0.00%
Effective tax rate		19.50%	22.50%	24.30%

[1] The statutory rate for 2016, 2015 and 2014 reflects the U.K. statutory rate of 20.0 percent, 20.3 percent and 21.0 percent, respectively.