CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net (loss) income	$ (12,183)	$ 82,480
Less: gain on sale of business	13,713	0
Less: net income from discontinued operations	10,523	4,574
Net (loss) income from continuing operations	(36,419)	77,906
Adjustments to reconcile net (loss) income to net cash provided by operating activities of continuing operations:
Depreciation	33,437	29,404
Amortization of intangible assets	43,982	41,456
Amortization of debt issuance costs and debt discount	7,370	9,910
Inventory fair value purchase accounting adjustment	1,057	720
Loss on extinguishment of debt	58,475	0
Provision for doubtful accounts	1,810	1,721
Stock-based compensation	2,175	1,902
Reduction in tax receivable agreement	(1,189)	(68,033)
Unrealized gain on derivative instruments, net	(265)	(13,059)
Loss on disposal of property and equipment	552	200
Deferred income taxes	221	(6,263)
Change in assets and liabilities, net of effects of acquisitions:
Accounts receivable	(23,326)	4,602
Other receivables	(1,721)	(3,610)
Inventories	(8,834)	(10,449)
Prepaid expenses and other current assets	2,708	378
Other assets	(1,320)	2,970
Accounts payable	(1,951)	19,362
Accrued payroll and employee benefits	11,105	(5,351)
Accrued taxes	4,893	(1,528)
Other liabilities	(16,911)	(12,186)
Net cash provided by operating activities from continuing operations	75,849	70,052
Cash flows from investing activities from continuing operations:
Purchases of property and equipment	(34,892)	(28,249)
Payment of net working capital adjustments related to acquisitions	(40)	(405)
Proceeds from net working capital adjustments related to acquisitions	154	8,602
Proceeds from the disposal of fixed assets	2,315	2,586
Acquisitions, net of cash acquired	(93,477)	(73,038)
Net cash used in investing activities from continuing operations	(125,940)	(90,504)
Cash flows from financing activities from continuing operations:
Proceeds from asset-based revolving credit facility	897,911	400,239
Repayments of asset-based revolving credit facility	(799,272)	(561,509)
Term loan proceeds	450,000	0
Principal payments on long-term debt	(575,000)	0
Prepayment premium on bond	(23,872)	0
Debt issuance costs and deferred finance costs	(7,935)	0
Tax withholding payment related to net settlement of equity awards	(61)	0
Principal repayment of capital lease obligations	(2,771)	(2,582)
Issuance of common stock	0	163,952
Capital contributions	0	2,997
Net cash (used in) provided by financing activities from continuing operations	(61,000)	3,097
Net cash (used in) provided by operating activities from discontinued operations	(6,614)	7,209
Net cash provided by (used in) investing activities from discontinued operations	121,568	(6,434)
Net cash used in financing activities of discontinued operations	(162)	(255)
Net cash provided by discontinued operations	114,792	520
Effect of exchange rate changes on cash	(503)	384
Net increase (decrease) in cash	3,198	(16,451)
Cash and cash equivalents at beginning of period	15,299	12,101
Cash and cash equivalents at end of period	12,101	28,552
Supplemental disclosures of cash flow information:
Cash paid for income taxes	2,507	4,129
Cash paid for interest	61,199	50,866
Supplemental disclosures of non-cash investing and financing activities:
Change in fair value of derivatives, net of tax	4,616	2,970
Assets acquired under capital lease	0	670
Goodwill adjustment for purchase price allocation	202	519
Tax receivable agreement	0	203,837
Embedded derivative in issued notes	0	0
Notes received for disposals of equipment	$ 0	$ 134