Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 19,933	$ 19,918	$ 18,244
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,291	4,317	5,131
(Gain) loss on disposals of property and equipment, net	(19)	17	(27)
Loss on disposal of intangibles	225	215	168
Bond premium amortization	1,650	957	289
Stock-based compensation	7,263	5,579	4,340
Deferred income taxes	994	3,598	621
Unrecognized tax benefits	(156)	202	219
Excess tax benefit from stock-based compensation	(6,936)	(7,985)	(6,797)
Change in assets and liabilities:
Accounts and notes receivable	4,244	(8,247)	(4,387)
Inventory	3,140	(7,214)	(116)
Prepaid expenses and other assets	(8,579)	(1,080)	(569)
Accounts payable, accrued and other liabilities	5,868	9,852	6,560
Deferred revenue	15,289	15,469	8,096
Customer deposits	238	(166)	654
Net cash provided by operating activities	46,445	35,432	32,426
Cash flows from investing activities:
Purchases of investments	(62,464)	(32,900)	(29,112)
Proceeds from call / maturity of investments	44,105	10,997	9,380
Purchases of property and equipment	(6,003)	(2,505)	(1,783)
Proceeds from disposal of fixed assets	40	10	34
Purchases of intangible assets	(501)	(183)	(323)
Business acquisitions, net of cash acquired	(11,186)	0	(1,258)
Net cash used in investing activities	(36,009)	(24,581)	(23,062)
Cash flows from financing activities:
Repurchase of common stock	(7,556)	(22,442)	(25,000)
Proceeds from options exercised	2,673	11,000	15,357
Payroll tax payments for net-settled stock awards	(1,370)	(1,347)	(309)
Payments on capital lease obligation	(80)	(36)	(34)
Excess tax benefit from stock-based compensation	6,936	7,985	6,797
Net cash provided by (used in) financing activities	603	(4,840)	(3,189)
Effect of exchange rate changes on cash and cash equivalents	120	85	(31)
Net increase in cash and cash equivalents	11,159	6,096	6,144
Cash and cash equivalents, beginning of year	48,367	42,271	36,127
Cash and cash equivalents, end of year	$ 59,526	$ 48,367	$ 42,271