Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income	$ 21,468	$ 7,906
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	20,823	5,331
Change in fair value of contingent consideration	(1,660)	657
Contingent consideration payment	(3,738)
Net provision for doubtful accounts	3,307	3,257
Share-based compensation expense	2,502	1,828
Excess tax benefits related to share-based awards	(14,348)
Deferred tax expense	1,185	3,286
Amortization of debt issuance costs	665	276
Impairment of capitalized software for internal use	150
Loss (gain) on sale or disposal of property and equipment	60	(11)
Change in fair value of redeemable common shares		(7,873)
Termination of existing stock redemption agreement		4,842
Equity loss of non-consolidated entity		1,087
Changes in operating assets and liabilities, net of business acquisitions:
Accounts receivable	(43,513)	(18,563)
Inventories	(28,379)	(6,913)
Accounts payable	18,644	26,192
Other assets and liabilities	25,366	(1,998)
Net cash provided by operating activities	2,532	19,304
Cash flows from investing activities:
Payments to acquire business, net of cash acquired	(299,534)	(51,599)
Expenditures for capitalized software for internal use	(9,145)	(5,758)
Expenditures for property and equipment	(2,374)	(834)
Net proceeds from sales of property and equipment	8	21
Loan to non-consolidated entity		(500)
Net repayment of related parties' notes receivable		150
Net cash used in investing activities	(311,045)	(58,520)
Cash flows from financing activities:
Net borrowings from line of credit	21,756	13,940
Proceeds from long-term debt	120,000
Payments on long-term debt	(1,500)	(5,693)
Proceeds from follow-on public offering, net of transaction costs	187,238
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	8,745
Excess tax benefits related to share-based awards	14,348
Payments of debt issuance costs	(5,056)
Contingent consideration payment	(3,012)
Payments of stock offering costs		(1,368)
Net cash provided by financing activities	306,221	45,894
Net (decrease) increase in cash and equivalents	(2,292)	6,678
Cash and equivalents at beginning of period	17,957	9,109
Cash and equivalents at end of period	15,665	15,787
Supplemental disclosures of cash flow information:
Cash paid for interest	2,730	1,411
Cash paid for income taxes	$ 346	$ 3,426