Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income (loss)	$ 24,772	$ 4,551	$ (26,120)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	30,841	8,139	3,934
Changes in fair values of contingent consideration	6,724	6,121
Contingent consideration payments	(3,738)
Net provision for doubtful accounts	5,990	4,045	873
Share-based compensation expense	3,936	2,871	886
Excess tax benefits related to share-based awards	(20,805)	(3,689)
Deferred income tax benefit	(4,615)	(1,295)
Amortization of debt issuance costs	963	366	204
Asset impairment	150		932
Loss on sale or disposal of property and equipment	85	132	13
Change in fair value of redeemable common shares		(9,073)	34,348
Equity loss and impairment of non-consolidated entity		6,208	1,055
Termination of existing stock redemption agreement		4,842
Changes in operating assets and liabilities, net of business acquisitions:
Accounts receivable	(50,771)	(43,130)	(29,774)
Inventories	(41,657)	(50,334)	(14,109)
Accounts payable	43,202	56,505	36,138
Other assets and liabilities	34,370	4,173	(2,153)
Net cash provided by (used in) operating activities	29,447	(9,568)	6,227
Cash flows from investing activities:
Payments to acquire business, net of cash acquired	(293,496)	(51,599)	(10,232)
Expenditures for capitalized software for internal use	(12,021)	(9,470)	(4,679)
Expenditures for property and equipment	(4,624)	(1,487)	(852)
Capital investments in and loans to non-consolidated entities	(1,459)	(4,000)	(4,500)
Other	27	472	(29)
Net cash used in investing activities	(311,573)	(66,084)	(20,292)
Cash flows from financing activities:
Net (payments on) borrowings from line of credit		(62,622)	35,602
Proceeds from long-term debt	120,000
Payments on long-term debt	(3,000)	(25,542)	(10,540)
Proceeds from public offering, net of transaction costs	187,988	130,440
Proceeds from sale of preferred stock, net of transaction costs		101,815
Payments made to repurchase common stock		(53,400)
Payments made to repurchase stock options	(36,298)	(9,400)
Proceeds from issuance of stock upon stock option exercises	10,341
Excess tax benefits related to share-based awards	20,805	3,689
Payments of debt issuance costs	(5,055)	(480)	(204)
Contingent consideration payments	(3,012)
Shareholder distributions			(1,684)
Net cash provided by financing activities	291,769	84,500	23,174
Net (decrease) increase in cash and equivalents	9,643	8,848	9,109
Cash and equivalents at beginning of year	17,957	9,109
Cash and equivalents at end of year	27,600	17,957	9,109
Supplemental disclosures of cash flow information:
Cash paid for interest	3,949	2,248	$ 1,793
Cash paid for income taxes	$ 351	$ 5,924