Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Operating loss carryforwards, federal	$ 180,621,000
Operating loss carryforwards, state	17,850,000
Deferred tax assets, valuation allowance	90,278,000	$ 102,627,000
Federal NOL annual utilization limit	14,100,000
Deferred Tax Asset, Operating and Capital Loss Carryforwards and Credits	90,871,000	$ 83,323,000
Foreign tax credits, additional paid in capital benefit	$ 51,126,000
Effective Income Tax Rate Reconciliation, Percent	12.00%	50.00%	3.00%
Effective tax rate excluding valuation allowance	47.00%	(33.00%)	(28.00%)
Deferred Tax Liabilities, Other	$ 10,587,000
Federal Deferred Tax Asset, Impact of ASU 2016-09	21,350,000
Deferred Tax Assets, Gross	100,889,000	$ 102,789,000
Deferred Tax Assets, State Taxes	1,559,000
Unrecognized tax benefits	808,000
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount	0.21
Deferred Tax Asset, Revaluation	25,261,000
Domestic Tax Authority [Member]
Income Taxes [Line Items]
Net operating losses included in deferred tax assets	2,804,000
Capital Loss Carryforward Related to Business Acquisition [Member] | Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Operating Loss Carryforwards	$ 26,326,000