Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Cash flows from operating activities:
Net income	$ 74,120	$ 28,214
Adjustments to reconcile net income to cash flows provided by operating activities:
Depreciation and amortization	24,516	24,614
Stock-based compensation expense	7,436	3,295
Other non-cash items	1,318	(2,231)
Changes in assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(139,245)	(74,776)
Inventories, net	(41,170)	40,883
Prepaid expenses and other assets	(3,328)	6,350
Accounts payable, trade	49,644	31,878
Accrued expenses and other liabilities	31,556	(13,468)
Net cash flows provided by operating activities	4,847	44,759
Cash flows from investing activities:
Capital expenditures	(20,957)	(7,955)
Acquisitions of businesses, net of cash acquired	(2,779)	(95,766)
Other investing activities	(605)	1,972
Net cash flows used in investing activities	(24,341)	(101,749)
Cash flows from financing activities:
Vesting of stock-based awards, net of shares tendered for payment of taxes	(7,767)	(4,517)
Proceeds from revolving credit facility	208,863	247,154
Repayments under revolving credit facility	(141,489)	(102,330)
Repayments under term loan and other borrowings	(3,889)	(3,750)
Payment of dividends	(18,939)	(16,321)
Payment of contingent consideration and holdbacks related to acquisitions	(2,792)	0
Other financing activities	0	(391)
Net cash flows provided by financing activities	33,987	119,845
Effect of exchange rate changes on cash and cash equivalents	(2,995)	(215)
Net increase in cash and cash equivalents	11,498	62,640
Cash and cash equivalents at beginning of period	51,821	35,359	$ 35,359
Cash and cash equivalents cash at end of period	63,319	97,999	$ 51,821
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	3,564	5,536
Cash received during the period for income taxes, net of payments	(86)	(73)
Purchase of property and equipment in accrued expenses	$ 3,787	$ 2,459