Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities
Net income	$ 2,495	$ 54,455	$ 23,503
Adjustment to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	16,266	12,796	10,427
Write-off of deferred financing costs from early payoff of debt	0	0	1,443
Share-based compensation	18,147	11,111	6,758
Provision for doubtful accounts	346	231	46
Amortization of premiums on marketable securities	1,889	323	0
Change in fair value of warrant liabilities	0	0	(3,117)
Change in fair value of embedded derivative	0	0	2,785
Deferred income tax (benefit) expense	2,592	(37,612)	(14,185)
Other	126	21	5
Change in operating assets and liabilities:
Trade and other receivables	(933)	(3,127)	(2,766)
Prepaid expenses and other current assets	(880)	(1,080)	1,334
Other non-current assets	280	328	(1,305)
Accounts payable	9,029	518	(2,945)
Accrued expenses and other liabilities	31,655	6,920	5,913
Deferred revenue	26,100	28,115	20,782
Other non-current liabilities	2,066	4,374	(255)
Net cash provided by operating activities	109,178	77,373	48,423
Investing activities
Acquisition of businesses, net of cash acquired	0	(42,369)	(157,430)
Acquisition of property and equipment	(14,574)	(10,417)	(7,498)
Purchases of marketable securities	(135,178)	(50,775)	0
Sale and maturities of marketable securities	56,060	1,353	0
Premiums paid for company-owned life insurance policies	(4,337)	0	0
Decrease in restricted cash	0	0	1,748
Net cash used in investing activities	(98,029)	(102,208)	(163,180)
Proceeds from:
Term loan	0	0	68,000
Initial public offering, net of offering costs	0	0	125,663
Issuance of convertible redeemable preferred stock, net of offering costs	0	0	102,165
Issuance of warrants	0	0	4,373
Exercise of warrants	375	0	0
Stock based compensation plans	12,241	15,425	298
Payments for:
Term loan	0	0	(68,000)
Payments to Series E-1 convertible redeemable preferred stockholders	0	0	(10,719)
Employee tax withholdings related to restricted stock units and awards	(1,107)	(436)	0
Debt issuance costs	0	(440)	(1,676)
Net cash provided by (used in) financing activities	11,509	14,549	220,104
Net increase (decrease) in cash and cash equivalents	22,658	(10,286)	105,347
Cash and cash equivalents at beginning of year	123,911	134,197	28,850
Cash and cash equivalents at end of year	146,569	123,911	134,197
Cash paid during the period for:
Interest	161	267	1,836
Income taxes	(235)	1,121	518
Supplemental information for non-cash investing activities:
Accrued capital expenditures	1,835	1,300	127
Property and equipment acquired through leasehold incentives	284	0	0
Supplemental information for non-cash financing activities:
Convertible redeemable preferred stock issued as part of purchase price for ID Analytics	0	0	11,542
Preferred stock embedded derivative issued as part of purchase price for ID Analytics	$ 0	$ 0	$ 7,934