Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation Allowance [Line Items]
Federal income tax at statutory rate	35.00%	35.00%	35.00%
Increase (decrease) in current income tax expense	$ 62,900,000	$ (60,500,000)
Change in valuation allowance	0	(64,159,000)	$ (5,087,000)
Decrease in income taxes due to decrease in net income	1,200,000
Decrease in income before income taxes	3,300,000
Increase (decrease) in other changes	(100,000)	(1,400,000)
Increase (decrease) in valuation allowance		(59,100,000)
NOLs available for future years	125,700,000
Foreign tax credits	400,000
AMT minimum tax credit carryforwards	2,200,000
Deferred tax asset valuation allowance	0	$ 50,031,000
Reduction of DTA	$ 50,000,000
Amortization period	10 years
Foreign operations
Valuation Allowance [Line Items]
NOLs available for future years	$ 1,700,000
Minimum | State jurisdiction
Valuation Allowance [Line Items]
Statute of limitations	3 years
Maximum | State jurisdiction
Valuation Allowance [Line Items]
Statute of limitations	4 years
Valuation Allowance, Operating Loss Carryforwards [Member]
Valuation Allowance [Line Items]
Valuation allowance write-offs	$ 50,000,000