Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net income	$ 11,861	$ 9,976
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and asset write offs	5,982	6,408
Amortization of intangible assets	627	669
Net (gains) losses from investments	1,139	(236)
Deferred income taxes	(413)	(2,463)
Stock-based compensation	5,731	5,885
Amortization of premium on investments	267	556
Foreign currency losses	98	64
Changes in assets and liabilities
Accounts receivable	31,078	29,511
Deferred commissions	3,890	4,422
Prepaid expenses and other current assets	1,977	(148)
Accounts payable	133	(284)
Accrued expenses and other liabilities	(12,170)	(7,115)
Deferred revenue	(14,309)	(19,027)
Net cash provided by operating activities	35,891	28,218
Cash flows from investing activities:
Purchases of property and equipment	(3,334)	(2,316)
Purchases of marketable investments	(35,555)	(20,587)
Proceeds from sales and maturities of marketable investments	20,086	16,428
Other investing activity	(49)	275
Net cash used in investing activities	(18,852)	(6,200)
Cash flows from financing activities:
Dividends paid on common stock	(9,696)	(9,163)
Repurchases of common stock		(18,639)
Proceeds from issuance of common stock under employee equity incentive plans	9,987	2,899
Excess tax benefits from stock-based compensation	345	32
Net cash provided by (used in) financing activities	636	(24,871)
Effect of exchange rate changes on cash and cash equivalents	(870)	(1,211)
Net increase (decrease) in cash and cash equivalents	16,805	(4,064)
Cash and cash equivalents, beginning of period	53,331	49,650
Cash and cash equivalents, end of period	$ 70,136	$ 45,586