Disclosures about Fair Value of Financial Instruments - Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Interest expense, net	$ (20,586)	$ (12,199)	$ (37,551)	$ (23,393)
Total	502,616		502,616		$ 133,379
Cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total	45,057		45,057		84,149
Commercial Paper
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total	94,835		94,835		0
Money market funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Interest expense, net	1,800	$ 200	4,000	$ 300
Total	$ 362,724		$ 362,724		$ 49,230