Income Taxes Deferred income tax provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Components of deferred tax provision [Line Items]
Deferred Income Tax Expense (Benefit)	$ (17,912)	$ (25,568)	$ (2,508)