Income Taxes (Gross Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance at beginning of period	$ 997	$ 915
Additions based on tax positions related to prior years	283	0
Additions based on tax positions related to the current year	0	82
Balance at end of period	$ 1,280	$ 997