Stock Based Compensation (Stock based compensation expense) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation		$ 3,014	$ 3,310	$ 9,177	$ 8,226
Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation	[1]	3,014	3,281	9,177	8,049
Restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation		0	2	0	100
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation		$ 0	$ 27	$ 0	$ 77

[1] Includes service-based and performance-based restricted stock units.