Income Taxes - Income Tax Expense (Benefit) from Continuing Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
Federal	$ 6,304	$ 5,684	$ 6,677
Foreign	1,821	515	337
State and local	2,402	641	812
Current Income Tax Expense (Benefit)	10,527	6,840	7,826
Deferred
Federal	(4,394)	(413)	(368)
Foreign	(883)	741	1,308
State and local	(386)	227	(729)
Deferred Income Tax Expense (Benefit)	$ (5,663)	$ 555	$ 211