Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net loss	$ (173,763)	$ (4,414)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	41,459	48,170
Goodwill impairments	122,891
Impairments of definite-lived intangible assets	17,979
Share-based compensation expense	7,855	10,122
Net provision for doubtful accounts	5,567	3,919
Amortization of debt issuance costs	1,921	2,742
Net realizable value loss on assets held for sale	1,654
Changes in fair value of contingent consideration	(57)	2,339
Contingent consideration payment		(2,704)
Deferred income tax expense (benefit)	772	(632)
Changes in operating assets and liabilities:
Accounts receivable	(8,560)	(22,732)
Inventories	31,490	36,407
Accounts payable	18,460	(4,526)
Rebates payable	(2,300)	(3,487)
Other assets and liabilities	1,382	1,448
Net cash provided by operating activities	66,750	66,652
Cash flows from investing activities:
Expenditures for property and equipment	(2,845)	(5,487)
Expenditures for capitalized software for internal use	(10,707)	(5,878)
Net payments to acquire businesses, net of cash acquired		(1,289)
Other	21	46
Net cash used in investing activities	(13,531)	(12,608)
Cash flows from financing activities:
Net payments on revolving line of credit	(51,300)	(53,150)
Payments on long-term debt	(5,751)	(79,750)
Payments of debt issuance costs		(821)
Proceeds from issuance of stock upon stock option exercises	118	3,351
Contingent consideration payment		(565)
Net cash used in financing activities	(56,933)	(130,935)
Net decrease in cash and equivalents	(3,714)	(76,891)
Cash and equivalents at beginning of period	9,485	84,251
Cash and equivalents at end of period	5,771	7,360
Supplemental disclosures of cash flow information:
Cash paid for interest	18,464	18,589
Cash (refunded) paid for income taxes		$ 1,741
Cash (refunded) paid for income taxes	$ (713)