Accrued Product Returns and Rebates (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accrued Product Returns and Rebates
Accrued product rebates	$ 118,335	$ 88,811
Accrued product returns	25,770	18,818
Total	$ 144,105	$ 107,629