Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income (loss)	$ (9,570)	$ 15,380	$ 15,140
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	8,572	7,955	6,648
Amortization of intangible assets	22,619	1,162	781
Net (gains) losses from investments	(45)	(426)	479
Deferred income taxes	(3,957)	2,931	6,425
Stock-based compensation	11,684	8,300	8,490
Operating lease right-of-use asset amortization and impairments	12,592
Amortization of deferred financing fees	968
Amortization of premium (discount) on investments		(68)	207
Foreign currency losses	933	603	632
Changes in assets and liabilities, net of businesses acquired
Accounts receivable	3,696	2,588	(10,327)
Deferred commissions	(4,643)	(1,077)	(1,679)
Prepaid expenses and other current assets	(3,697)	285	(4,146)
Accounts payable	278	172	(1,600)
Accrued expenses and other liabilities	4,421	1,217	7,857
Deferred revenue	15,508	(604)	8,586
Operating lease liabilities	(10,953)
Net cash provided by operating activities	48,406	38,418	37,493
Cash flows from investing activities:
Acquisitions, net of cash acquired	(237,684)	(9,250)
Purchases of property and equipment	(11,890)	(5,049)	(7,861)
Purchases of marketable investments		(41,810)	(31,910)
Proceeds from maturities of marketable investments		63,627	31,913
Proceeds from sales of marketable investments		32,568	6,545
Other investing activity	29		343
Net cash provided by (used in) investing activities	(249,545)	40,086	(970)
Cash flows from financing activities:
Proceeds from borrowings, net of costs	171,275
Payments on borrowings	(42,250)
Payment of debt issuance costs	(857)
Deferred acquisition payments	(2,799)
Dividends paid on common stock		(14,502)	(13,631)
Repurchases of common stock		(9,946)	(39,967)
Proceeds from issuance of common stock under employee equity incentive plans	6,327	13,020	18,506
Taxes paid related to net share settlements of stock-based compensation awards	(2,258)	(2,526)	(2,527)
Net cash provided by (used in) financing activities	129,438	(13,954)	(37,619)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	597	(4,044)	3,928
Net increase in cash, cash equivalents and restricted cash	(71,104)	60,506	2,832
Cash, cash equivalents and restricted cash, beginning of year	140,296	79,790	76,958
Cash, cash equivalents and restricted cash, end of year	69,192	140,296	79,790
Supplemental disclosure of cash flow information:
Cash paid for interest	7,003
Cash paid for income taxes	$ 4,433	$ 4,174	$ 10,433