Other Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Other Assets, Noncurrent [Abstract]
Deferred income taxes	$ 25,108	$ 61,132
Assets related to unrecognized tax benefits	14,601	15,076
Other	34,455	66,112
Total	74,164	$ 142,320
Note receivable reserve	$ 28,700