Consolidated Statement of Cash Flows Statement - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows from Operating Activities:
Net income (loss)	$ 83,300	$ 30,960	$ (39,800)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Impairment of goodwill and indefinite-lived intangible assets	0	0	98,900
Loss on dispositions of assets	250	1,080	1,870
Depreciation	24,580	26,950	24,390
Amortization of intangible assets	19,440	19,920	20,470
Amortization of debt issue costs	1,290	1,320	1,370
Deferred income taxes	7,200	15,260	(32,160)
Non-cash compensation expense	7,170	6,780	6,940
Debt financing and related expenses	0	6,640	0
(Increase) decrease in receivables	(11,420)	1,220	7,990
(Increase) decrease in inventories	(18,690)	4,350	5,180
(Increase) decrease in prepaid expenses and other assets	9,060	(310)	2,550
Increase (decrease) in accounts payable and accrued liabilities	4,340	3,640	(18,120)
Other operating activities	2,800	2,250	890
Net cash provided by operating activities	129,320	120,060	80,470
Cash Flows from Investing Activities:
Capital expenditures	(25,050)	(36,800)	(31,330)
Net proceeds from dispositions of property and equipment	250	4,450	220
Net cash used for investing activities	(24,800)	(32,350)	(31,110)
Cash Flows from Financing Activities:
Proceeds from borrowings on revolving credit and accounts receivable facilities	59,060	401,300	402,420
Repayments of borrowings on revolving credit and accounts receivable facilities	(68,490)	(517,310)	(433,350)
Payments to purchase common stock	12,140	0	0
Shares surrendered upon exercise and vesting of equity awards to cover taxes	(2,380)	(510)	(1,590)
Proceeds from issuance of senior notes	0	300,000	0
Repayments of borrowings on term loan facilities	0	(257,940)	(13,850)
Debt financing fees	0	(6,070)	0
Payments for deferred purchase price	0	0	(2,530)
Other financing activities	0	(310)	800
Net cash used for financing activities	(23,950)	(80,840)	(48,100)
Increase for the year	80,570	6,870	1,260
At beginning of year	27,580	20,710	19,450
At end of year	108,150	27,580	20,710
Supplemental disclosure of cash flow information:
Cash paid for interest	13,800	9,430	11,800
Cash paid for income taxes	$ 7,380	$ 16,230	$ 17,210