Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016
Operating activities
Net income		$ 38,594	$ 31,155
Adjustment to reconcile net income to net cash provided by operating activities:
Depreciation		11,271	10,429
Amortization of intangible assets		14,312	16,014
Amortization of original issue discount and deferred financing costs		1,308	2,122
Deferred income taxes		17,164	9,072
Share-based compensation expense	[1]	5,818	5,386
Other		377	46
Net changes in operating assets and liabilities, net of acquisitions:
Accounts receivable		5,362	(9,389)
Inventories		(13,981)	(1,046)
Other assets		1,069	2,297
Accounts payable		(26,560)	17,537
Accrued wages and employee benefits		1,902	6,166
Other accrued liabilities		(559)	(1,825)
Excess tax benefits from equity awards		(403)	(6,729)
Net cash provided by operating activities		55,674	81,235
Investing activities
Proceeds from sale of property and equipment		45	47
Expenditures for property and equipment		(10,030)	(14,004)
Acquisitions of businesses, net of cash acquired		1,160	(60,886)
Net cash used in investing activities		(8,825)	(74,843)
Financing activities
Proceeds from short-term borrowings		62,435	10,278
Proceeds from long-term borrowings		3,069
Repayments of short-term borrowings		(72,971)	(6,327)
Repayments of long-term borrowings and capital lease obligations		(9,806)	(10,652)
Stock repurchases		(30,012)	(34,576)
Payment of debt issuance costs		(1,517)
Cash dividends paid			(76)
Taxes paid related to the net share settlement of equity awards		(1,958)	(12,099)
Proceeds from exercise of stock options		1,254
Excess tax benefits from equity awards			6,729
Net cash used in financing activities		(49,506)	(46,723)
Effect of exchange rate changes on cash and cash equivalents		2,456	115
Net decrease in cash and cash equivalents		(201)	(40,216)
Cash and cash equivalents at beginning of period		67,272	115,857
Cash and cash equivalents at end of period		$ 67,071	$ 75,641

[1] Represents share-based compensation expense to account for stock options, restricted stock and other stock awards over their respective vesting periods.