Changes in Operations Europe - ERS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Goodwill, Impairment Loss					$ 14,482
Restructuring costs	$ 2,361	$ 4,970	$ 6,116	$ 6,097
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			$ 4,500
ERS Railways [Member] | U.K./European Operations [Member] | Customer Relationships [Member]
Impairment of Intangible Assets, Finite-lived					$ 4,100