Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income (loss)	$ (19,612)	$ 2,148
Adjustments to reconcile net income to net cash used in operating activities:
Stock-based compensation	10,031	6,876
Depreciation And Amortization	3,539	2,719
Amortization of acquired intangible	611	611
Impairment charges and loss on disposal of long-lived assets	100	312
Amortization of net premium on investments	652	1,073
Amortization of warrant issuance costs	16	16
Changes in operating assets and liabilities:
Disbursement prefunding	16,608	(45,041)
Customer funds receivable	(6,042)	(17,093)
Prepaid expenses and other current assets	(2,282)	(868)
Other assets	108	288
Customer liabilities	799	10,501
Accounts payable and accrued expenses	2,366	864
Non-current liabilities	284	1,945
Net cash provided by operating activities	7,178	(35,649)
Cash flows from investing activities:
Purchase of property, equipment, software, and intangible assets	(4,630)	(10,793)
Purchase of short-term investments	(73,502)	(108,896)
Proceeds from sales and maturities of short-term investments	97,061	109,269
Cash paid in business combination, net of cash received	(1,500)	(8,874)
Change in restricted cash	(2,783)	(3,154)
Net cash provided by (used in) investing activities	14,646	(22,448)
Cash flows from financing activities:
Proceeds from exercise of common stock options	4,983	3,003
Excess tax benefit related to stock-based compensation		23
Taxes paid related to net share settlement	(1,197)
Net borrowings (repayments) under line of credit	(28,000)	38,000
Net cash provided by (used in) financing activities	(24,214)	41,026
Net increase (decrease) in cash and cash equivalents	(2,390)	(17,071)
Cash and cash equivalents, beginning of period	67,216	110,979
Cash and cash equivalents, end of period	64,826	93,908
Supplemental disclosures of cash flow information:
Cash paid for taxes	114	2
Cash paid for interest	782	767
Cash received from refund of income taxes	17
Supplemental disclosure of non-cash investing and financing activities:
Issuance of common stock in connection with acquisition of BlueKite, LTD		4,470
Purchases of property and equipment in accounts payable and accrued expenses	$ 808	$ 2,225