Supplemental balance sheet information related to leases (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Operating lease right-of-use assets	$ 34,717	$ 39,256	$ 34,230
Current portion of operating lease liabilities	9,014	9,823	8,394
Long-term operating lease liabilities	22,709	25,893	23,465
Total operating lease liabilities	$ 31,723	$ 35,716	$ 31,859