Income Taxes Unrecognized Tax Benefits Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1	$ 1,025	$ 974	$ 1,022
Additions based on tax positions related to the current year	149	183	160
Additions based on tax positions taken in prior years	0	227	0
Decreases based on the expiration of statute of limitations	(239)	(359)	(208)
Balance at December 31	$ 935	$ 1,025	$ 974