Revenue Recognition - Product Revenue Allowance and Accrual Activity (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Contractual Adjustments
Balance at Beginning of Period	$ 57,199
Provisions related to current period sales	107,388
Adjustments related to prior period sales	1,540
Payments/returns relating to current period sales	(65,839)
Payments/returns relating to prior period sales	(27,275)
Balance at End of Period	73,013
Governmental Rebates
Balance at Beginning of Period	29,114
Provisions related to current period sales	18,502
Adjustments related to prior period sales	8,603
Payments/returns relating to current period sales	0
Payments/returns relating to prior period sales	(14,292)
Balance at End of Period	41,927
Revenue, Allowance [Roll Forward]
Balance at Beginning of Period	86,313
Provisions related to current period sales	125,890
Adjustments related to prior period sales	10,143
Payments/returns relating to current period sales	(65,839)
Payments/returns relating to prior period sales	(41,567)
Balance at End of Period	$ 114,940