Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclsoure [Line Items]
Additional federal tax	$ 9,100
Foreign loss carryforwards	16,100
Decrease in current taxes payable	800
Deferred tax asset net of valuation allowance	62,108	$ 56,072
Income taxes receivable	$ 1,400	$ 3,600
U.S. statutory tax rate	35.00%	35.00%	35.00%
Foreign Tax Authority | Her Majesty's Revenue and Customs (HMRC)
Income Tax Disclsoure [Line Items]
Deferred tax asset net of valuation allowance	$ 1,900
Minimum
Income Tax Disclsoure [Line Items]
Carryforward period	9 years