Income Taxes (Reconciliation of Gross Unrecognized Tax Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of gross unrecognized tax benefits
Gross unrecognized tax benefit balance at beginning of year	$ 6,495	$ 7,574	$ 3,612
Change in tax positions of prior years			3,543
Change in tax positions of prior years	(302)	(1,207)
Change in tax positions of current year	763	128	419
Reduction in tax positions for statute expirations	(1,958)
Gross unrecognized tax benefit balance at end of year	$ 4,998	$ 6,495	$ 7,574