Discontinued Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	$ (5,093)	$ 3,800	$ 3,200
Liabilities
Employee compensation and benefits	17,880	19,885
Post-retirement	4,652	5,663
Total Liabilities	$ 22,532	$ 25,548