Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 13,186	$ 28,214	$ 47,527	$ 34,366	$ 41,400	$ 81,893
Adjustments to reconcile net income to cash flows provided by operating activities:
Depreciation and amortization					48,799	37,115
Stock-based compensation expense					7,404	7,848
Other non-cash items					546	705
Changes in assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net					(62,611)	(22,345)
Inventories, net					63,404	39,944
Prepaid expenses and other assets					(27,679)	11,444
Accounts payable, trade					20,917	11,567
Accrued expenses and other liabilities					9,921	11,944
Net cash flows provided by operating activities					102,101	180,115
Cash flows from investing activities:
Capital expenditures					(14,549)	(35,786)
Acquisitions of businesses, net of cash acquired					(94,713)	(8,530)
Other investing activities					4,096	251
Net cash flows used in investing activities					(105,166)	(44,065)
Cash flows from financing activities:
Exercise of stock-based awards, net of shares tendered for payment of taxes					(4,616)	(7,144)
Proceeds from line of credit borrowings					276,542	305,288
Repayments under line of credit borrowings					(197,330)	(354,981)
Repayments under term loan and other borrowings					(9,554)	0
Payment of dividends					(32,670)	(31,266)
Other financing activities					(279)	(397)
Net cash flows provided by (used in) financing activities					32,093	(88,500)
Effect of exchange rate changes on cash and cash equivalents					(2,115)	(1,818)
Net decrease in cash and cash equivalents					26,913	45,732
Cash, cash equivalents, and restricted cash at beginning of period		$ 35,359		$ 14,928	35,359	14,928	$ 14,928
Cash, cash equivalents, and restricted cash at end of period	$ 62,272		$ 60,660		62,272	60,660	$ 35,359
Supplemental disclosure of cash flow information:
Cash paid during the period for interest					9,593	3,948
Cash paid during the period for income taxes, net of refunds					(611)	13,890
Purchase of property and equipment in accrued expenses					$ 2,624	$ 298