Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Cash flow from operating activities:
Net income	$ 98,799	$ 122,268
Adjustments to reconcile net income to cash provided by operations:
Depreciation and amortization	16,539	14,284
Related party Tax Receivable Agreement expense (benefit)	47	(3,346)
Deferred income tax provision	(2,840)	6,348
Interest expense	5,309	1,594
Other charges, net	2,349	(838)
Net change in working capital*	25,187	27,727
Repayments Of Related Party Payable	(21,799)	(27,857)
Change in long-term assets and liabilities	(1,166)	(897)
Net cash provided by operating activities	122,425	139,283
Cash flow from investing activities:
Capital expenditures	(14,174)	(13,901)
Proceeds from the sale of assets	151	62
Net cash used in investing activities	(14,023)	(13,839)
Cash flow from financing activities:
Repurchase of common stock-non-related party	0	(30,099)
Principal repayments on long-term debt	(150,000)	0
Dividends paid to non-related-party	(1,394)	(5,926)
Dividends paid to related-party	(1,277)	(16,933)
Proceeds from (Payments for) Other Financing Activities	(1,120)	(46)
Net cash used in financing activities	(156,762)	(53,004)
Net change in cash and cash equivalents	(48,360)	72,440
Effect of exchange rate changes on cash and cash equivalents	(636)	(1,266)
Cash and cash equivalents at beginning of period	145,442	80,935	$ 80,935
Cash and cash equivalents at end of period	96,446	152,109	$ 145,442
* Net change in working capital due to changes in the following components:
Accounts and notes receivable, net	(16,643)	40,743
Inventories	11,648	(17,236)
Prepaid expenses and other current assets	(1,510)	7,411
Income taxes payable	(18,368)	14,238
Accounts payable and accruals	44,333	(17,388)
Interest payable	5,727	(41)
Net change in working capital	25,187	27,727
Payment Of Financing Costs and Debt Restructuring Costs	$ 2,971	$ 0