Income Taxes (Components of Income Tax Provision) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ (1,314)	$ 442	$ 3,944
State	675	(85)	390
Foreign	488	(526)	1,841
Total current	(151)	(169)	6,175
Deferred:
Federal	8,701	1,564	(2,628)
State	337	(112)	(63)
Foreign	(45)	(46)	(8)
Total deferred	8,993	1,406	(2,699)
Income tax expense	$ 8,842	$ 1,237	$ 3,476