Changes in Operations Europe - ERS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Goodwill, Impairment Loss					$ (14,482)
Restructuring costs	$ 2,628	$ 223	$ 8,744	$ 6,320
U.K./European Operations [Member]
Goodwill, Impairment Loss					(14,482)
ERS Railways [Member] | U.K./European Operations [Member]
Asset Impairment Charges					21,500
Goodwill, Impairment Loss					(14,500)
Restructuring costs			$ 5,200
ERS Railways [Member] | U.K./European Operations [Member] | Customer Relationships [Member]
Impairment of Intangible Assets, Finite-lived					$ 4,100