Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes Disclosure [Line Items]
Federal Statutory rate	35.00%	35.00%	35.00%
Increase in total stake holders equity	$ 2,900,000
Operating loss carryforwards	$ 230,000,000
Operating loss carryforwards, expiration date start	2028
Operating loss carryforwards, expiration date end	2036
Net operating loss carryforwards, majority expiration date start	2024
Net operating loss carryforwards, majority expiration date end	2036
Valuation allowance - state NOL carryforwards	$ 5,318,000	$ 290,000
Foreign tax credits	$ 21,500,000
Foreign tax credits, expiration date	2026
Valuation allowance - tax credit carryforwards	$ 11,000,000
Valuation allowance - tax credit carryforwards recorded in 2014	9,000,000
Income taxes paid	2,637,000	$ 5,521,000	$ 9,590,000
Unrecognized tax benefits	0
State and Local Jurisdiction [Member]
Income Taxes Disclosure [Line Items]
Operating loss carryforwards	$ 198,100,000
Operating loss carryforwards, expiration date end	2036
Valuation allowance - state NOL carryforwards	$ 5,300,000
State and Local Jurisdiction [Member] | Valuation Allowance, Operating Loss Carryforwards [Member]
Income Taxes Disclosure [Line Items]
Valuation allowance - state NOL carryforwards	$ 5,000,000