Accounts Receivable, Sales and Allowances - Allowance for customer deduction (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Trade accounts receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 91,797	$ 77,141
Provision	508,068	641,435
Charges processed	(569,933)	(626,779)
Balance at end of period	29,932	91,797
Chargebacks
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	38,861
Balance at end of period	14,624	38,861
Chargebacks | Trade accounts receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	38,861	32,342
Provision	345,366	365,043
Charges processed	(369,603)	(358,524)
Balance at end of period	14,624	38,861
Commercial rebates
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	49,232
Balance at end of period	13,579	49,232
Commercial rebates | Trade accounts receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	49,232	39,233
Provision	147,173	257,917
Charges processed	(182,826)	(247,918)
Balance at end of period	13,579	49,232
Discounts and allowances
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	3,510
Balance at end of period	1,591	3,510
Discounts and allowances | Trade accounts receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	3,510	3,485
Provision	15,719	20,246
Charges processed	(17,638)	(20,221)
Balance at end of period	1,591	3,510
Doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	194
Balance at end of period	138	194
Doubtful accounts | Trade accounts receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	194	2,081
Provision	(190)	(1,771)
Charges processed	134	(116)
Balance at end of period	$ 138	$ 194