Income Taxes Effective tax rate (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
GILTItaxexpense	$ 2,363	$ 0	$ 0
GILTItaxexpensepercent	10.60%	0.00%	0.00%
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	$ 22,374	$ 51,283	$ 85,164
Income Tax Reconciliation, Income Tax Expense (Benefit), at Federal Statutory Income Tax Rate	4,699	17,950	29,807
Income Tax Reconciliation, State and Local Income Taxes	927	(403)	1,795
Income Tax Reconciliation, Tax Credits	(4,961)	(2,783)	(1,014)
Income Tax Reconciliation, Foreign Income Tax Rate Differential	$ (2,944)	$ 3,481	$ (135)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, State and Local Income Taxes	4.10%	(0.80%)	2.10%
Effective Income Tax Rate Reconciliation, Tax Credits	(22.20%)	(5.40%)	(1.20%)
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential	(13.20%)	6.80%	(0.10%)
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount	$ (11,040)	$ (18,958)	$ (7,720)
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Percent	(49.30%)	(37.00%)	(9.10%)
Effective Income Tax Rate, Continuing Operations	(28.70%)	(33.80%)	25.90%
Tax reform	$ 826	$ 3,076	$ 0
EffectiveIncomeTaxRateREconciliationTaxReform	0.037	0.060	0.000
EffectiveIncomeTaxRateReconciliationIPMigration	$ 3,252	$ 3,367	$ 0
EffectiveTaxRateReconciliationIPMigrationPercent	0.145	0.066	0.000
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	$ 3	$ 1,125	$ (1,786)
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent	0.10%	2.20%	(2.10%)
EffectiveIncomeTaxRateReconciliationBargainPurchaseGain	$ 0	$ (24,811)	$ 0
EffectiveTaxRateReconciliationBargainPurchaseGainPercent	(0.000)	(0.484)	(0.000)
Effectiveincometaxreconciliation,nondeductiblecompensation	$ 456	$ 595	$ 1,133
Effectivetaxratereconciliationnondeductiblecomppercent	2.00%	1.20%	1.30%