Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income	$ 54,105	$ 35,612
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	32,966	35,817
Amortization of debt issuance costs and debt discount	931	885
Losses from equity method investment	1,148	29
Amortization of deferred gain on terminated swaps	(632)	0
Loss on debt extinguishment	0	686
Share-based compensation	2,459	2,101
Deferred taxes	(457)	92
Change in assets and liabilities:
Trade receivables	(914)	1,420
Inventories	(7,627)	(872)
Prepaid expenses and other current assets	1,264	(350)
Accounts payable	(52)	(87)
Accrued and other current liabilities	1,089	4
Other long-term liabilities	(226)	(245)
Net cash provided by operating activities	84,054	75,092
Cash flows from investing activities:
Capital expenditures	(19,761)	(14,077)
Software purchased or developed	(1,359)	(183)
Proceeds from the sale of property, plant and equipment	125	0
Capital contributions to equity method investment	(548)	(1,929)
Distributions from equity method investment	468	641
Net cash used in investing activities	(21,075)	(15,548)
Cash flows from financing activities:
Proceeds from exercise of stock options	145	230
Tax withholdings on share-based compensation	(547)	(240)
Proceeds from debt refinancing	0	273,625
Disbursements for debt refinancing	0	(273,625)
Payments of financing costs	0	(649)
Principal payments for debt	(2,037)	(2,052)
Payments to repurchase common stock	(27,425)	(49,128)
Net cash used in financing activities	(29,864)	(51,839)
Effect of foreign exchange rates on cash and cash equivalents	(184)	707
Net change in cash and cash equivalents	32,931	8,412
Cash, beginning of period	72,521	51,536
Cash, end of period	$ 105,452	$ 59,948