Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Customer Accounts Receivable and Note Receivable	$ 20,000
Accounts receivable	6,798,943	$ 6,211,077
Allowances for doubtful accounts	(52,256)	(49,659)
Accounts receivable, net	$ 6,746,687	$ 6,161,418