Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income	$ 17,297	$ 19,933	$ 19,918
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,658	3,291	4,317
Purchase accounting adjustments to goodwill	520	0	0
Loss (gain) on disposals of property and equipment, net	42	(19)	17
Loss on disposal of intangible assets	21	225	215
Bond premium amortization	1,265	1,650	957
Stock-based compensation	9,369	7,263	5,579
Deferred income taxes	(5,167)	994	3,598
Unrecognized tax benefits	582	(156)	202
Tax benefit from stock-based compensation	(1,438)	(6,936)	(7,985)
Change in assets and liabilities:
Accounts and notes receivable	(13,297)	4,244	(8,247)
Inventory	(18,668)	3,140	(7,214)
Prepaid expenses and other assets	(29,069)	(8,579)	(1,080)
Accounts payable, accrued and other liabilities	17,584	5,868	9,852
Deferred revenue	34,304	15,289	15,469
Customer deposits	922	238	(166)
Net cash provided by operating activities	17,925	46,445	35,432
Cash flows from investing activities:
Purchases of investments	(56,086)	(62,464)	(32,900)
Proceeds from call / maturity of investments	64,951	44,105	10,997
Purchases of property and equipment	(4,957)	(6,003)	(2,505)
Proceeds from disposal of property and equipment	42	40	10
Purchases of intangible assets	(3,495)	(501)	(183)
Business acquisitions, net of cash acquired	(3,500)	(11,186)	0
Net cash used in investing activities	(3,045)	(36,009)	(24,581)
Cash flows from financing activities:
Repurchase of common stock	(33,746)	(7,556)	(22,442)
Proceeds from options exercised	478	2,673	11,000
Payroll tax payments for net-settled stock awards	(1,772)	(1,370)	(1,347)
Payments on capital lease obligation	(32)	(80)	(36)
Payments on notes payable	(75)	0	0
Payment of contingent consideration for business acquisition	(952)	0	0
Excess tax benefit from stock-based compensation	1,438	6,936	7,985
Net cash (used in) provided by financing activities	(34,661)	603	(4,840)
Effect of exchange rate changes on cash and cash equivalents	906	120	85
Net increase (decrease) in cash and cash equivalents	(18,875)	11,159	6,096
Cash and cash equivalents, beginning of year	59,526	48,367	42,271
Cash and cash equivalents, end of year	$ 40,651	$ 59,526	$ 48,367