Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash Flows from Operating Activities
Net income	$ 12,059	$ 6,345
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	5,338	4,941
Stock compensation expense	1,665	2,371
(Benefit of) provision for deferred income taxes	(216)	393
Other, net	411	2,456
Changes in operating assets and liabilities, excluding the effects of acquisitions:
Accounts receivable	(7,059)	(27,623)
Inventories	(6,004)	35
Other current assets and other assets	6,144	165
Accounts payable	(17,789)	5,332
Accrued expenses and other non-current liabilities	(37,561)	(31,903)
Net cash used in operating activities	(43,012)	(37,488)
Cash Flows from Investing Activities
Acquisitions, net of cash acquired	(54,539)	(264)
Net proceeds from sale of property and equipment	52	22
Purchases of property, plant, and equipment	(2,822)	(3,132)
Net cash used in investing activities	(57,309)	(3,374)
Cash Flows from Financing Activities
Long-term debt payments	0	(210,000)
Payment of debt issuance costs	0	(1,235)
Purchase of treasury stock at market prices	(4,184)	(2,151)
Net proceeds from issuance of common stock	24	139
Net cash used in financing activities	(4,160)	(213,247)
Effect of exchange rate changes on cash	(916)	612
Net decrease in cash and cash equivalents	(105,397)	(253,497)
Cash and cash equivalents at beginning of year	191,363	297,006
Cash and cash equivalents at end of period	$ 85,966	$ 43,509