Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accounts Payable and Accrued Liabilities, Current [Abstract]
Trade accounts payable	$ 110,074	$ 96,024
Returns and allowances	208,264	236,946
Rebates	140,184	144,860
Chargebacks	1,578	2,971
Accrued interest	101,085	130,182
Accrued payroll and related benefits	71,867	89,895
Accrued royalties and other distribution partner payables	111,347	122,028
Acquisition-related contingent consideration—current	20,974	36,514
Other	171,808	149,780
Total	$ 937,181	$ 1,009,200