Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts
Changes in valuation and qualifying accounts
Additions	$ 900
Balance at End of Period	900
Accounts Receivable Allowance
Changes in valuation and qualifying accounts
Balance at Beginning of Period	11,618	$ 2,728	$ 1,771
Additions	93,887	60,054	37,222
Deductions Charged to Reserves	(94,722)	(51,164)	(36,265)
Balance at End of Period	10,783	11,618	2,728
Rebates, Fees and Returns Reserves
Changes in valuation and qualifying accounts
Balance at Beginning of Period	43,892	4,819	3,448
Additions	120,293	52,548	11,850
Deductions Charged to Reserves	(119,023)	(13,475)	(10,479)
Balance at End of Period	$ 45,162	$ 43,892	$ 4,819