CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income	$ 35,708	$ 23,220
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	23,576	22,819
Amortization of debt issuance costs and debt discount	1,149	1,149
Gain on extinguishment of debt	(680)
Deferred income taxes	9,638	1,497
Stock compensation expense	2,659	2,890
Gain on sale of assets	(464)	(245)
Changes in assets and liabilities:
Receivables	22,703	(57,132)
Inventories	(38,603)	(85,958)
Other current assets	4,732	(9,481)
Other assets and liabilities	(1,319)	1,552
Accounts payable	47,371	4,376
Accrued liabilities	(100,395)	(83,012)
Net cash provided by (used in) operating activities	6,075	(178,325)
Cash flows from investing activities:
Purchases of property, plant and equipment	(21,524)	(20,113)
Proceeds from sale of property, plant and equipment	720	568
Net cash used in investing activities	(20,804)	(19,545)
Cash flows from financing activities:
Borrowings under revolving credit facility	374,000	555,000
Repayments under revolving credit facility	(331,000)	(399,000)
Repayments of long-term debt and other loans	(24,440)	(2,780)
Exercise of stock options	216	2,041
Repurchase of common stock	(2,450)	(4,855)
Net cash provided by financing activities	16,326	150,406
Net change in cash and cash equivalents	1,597	(47,464)
Cash and cash equivalents at beginning of period	10,127	57,533
Cash and cash equivalents at end of period	$ 11,724	$ 10,069