CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income	$ 102,312	$ 79,842
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	47,390	47,587
Amortization of debt issuance costs and debt discount	2,132	2,308
Loss on extinguishment of debt, net	1,498
Deferred income taxes	21,390	18,863
Stock compensation expense	6,038	6,428
Net gain on sale of assets and asset impairments	(1,023)	(326)
Changes in assets and liabilities:
Receivables	(47,113)	(177,765)
Inventories	(20,631)	(189,925)
Other current assets	7,271	(5,693)
Other assets and liabilities	1,057	2,498
Accounts payable	90,050	67,129
Accrued liabilities	(31,586)	(19,915)
Net cash provided by (used in) operating activities	178,785	(168,969)
Cash flows from investing activities:
Purchases of property, plant and equipment	(45,392)	(49,948)
Proceeds from sale of property, plant and equipment	4,620	1,075
Net cash used in investing activities	(40,772)	(48,873)
Cash flows from financing activities:
Borrowings under revolving credit facility	594,000	904,000
Repayments under revolving credit facility	(700,000)	(721,000)
Proceeds from issuance of notes	400,000
Repayments of long-term debt and other loans	(423,743)	(6,852)
Payments of loan costs	(7,278)
Exercise of stock options	1,883	2,212
Repurchase of common stock	(2,450)	(4,855)
Net cash provided by (used in) financing activities	(137,588)	173,505
Net change in cash and cash equivalents	425	(44,337)
Cash and cash equivalents at beginning of the period	10,127	57,533
Cash and cash equivalents at end of the period	$ 10,552	$ 13,196