Accounts Receivable Factoring Receivables Factored and Costs Incurred (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Transfers and Servicing [Abstract]
Total amount of accounts receivable factored without recourse	$ 94,284	$ 152,996	$ 267,987	$ 369,567
Costs incurred on sale of receivables without recourse	$ 148	$ 333	$ 473	$ 717