Segment Information - Eliminations Footnote (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Operating income (loss)
Operating income (loss)	$ 271,015	$ 283,855	$ 870,934	$ 671,942
Gross profit	396,518	408,503	1,261,190	1,024,922
Assets elimination
Accounts receivable	923,017		923,017		$ 729,784
Other	27,940		27,940		29,514
Total assets	6,960,737		6,960,737		$ 6,423,732
Eliminations
Operating income (loss)
Operating income (loss)	(692)	$ 91	(371)	$ (9,055)
Assets elimination
Accounts receivable	(130,400)		(130,400)
Elimination of intra-company debt	(10,700)		(10,700)
Other	(13,000)		(13,000)
Total assets	$ (154,084)		$ (154,084)