Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash Flows from Operating Activities:
Net income	$ 14,832	$ 12,869
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,368	4,036
Loss (gain) on disposal of property and equipment, net	17	(29)
Loss on write-down / disposal of intangible assets, net	211	113
Bond premium amortization	675	174
Provision for doubtful accounts	143	2
Provision for excess and obsolete inventory	20	279
Provision for warranty	517	644
Stock-based compensation expense	4,121	2,906
Deferred income taxes	9,862	5,212
Unrecognized tax benefits	(1,713)	172
Excess tax benefit from stock-based compensation	(5,849)	(4,058)
Change in assets and liabilities:
Accounts and notes receivable	(4,754)	(1,994)
Inventory	(5,039)	(1,575)
Prepaid expenses and other assets	(1,063)	(2,243)
Accounts payable and accrued liabilities	(1,705)	(496)
Deferred revenue	9,780	6,497
Customer deposits	(785)	578
Net cash provided by operating activities	22,638	23,087
Cash Flows from Investing Activities:
Purchases of investments	(23,613)	(18,450)
Proceeds from call / maturity of investments	8,668	6,625
Purchases of property and equipment	(2,066)	(1,174)
Proceeds from disposal of fixed assets	10	34
Purchases of intangible assets	(125)	(271)
Net cash used in investing activities	(17,126)	(13,236)
Cash Flows from Financing Activities:
Repurchase of common stock	(22,442)	(25,000)
Proceeds from options exercised	8,597	10,219
Payroll tax payments for net-settled stock awards	(1,262)	(221)
Excess tax benefit from stock-based compensation	5,849	4,058
Payments on capital lease obligation	(26)	(25)
Net cash used in financing activities	(9,284)	(10,969)
Effect of exchange rate change on cash and cash equivalents	116	(3)
Net decrease in cash and cash equivalents	(3,656)	(1,121)
Cash and cash equivalents, beginning of period	42,271	36,127
Cash and cash equivalents, end of period	38,615	35,006
Supplemental Disclosure:
Cash paid for income taxes-net	403	2,427
Non-Cash Transactions:
Property and equipment purchases in accounts payable	$ 158	$ 59