Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating Activities
Net income	$ 23,105	$ 21,282
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	18,457	14,705
Loss on disposal of fixed assets	114	221
Gain on business combination	(3,443)	0
Provision for receivable allowance	542	850
Share-based compensation expense	11,267	8,610
Income tax benefits from employee stock plans	3,838	4,065
Excess tax benefits from employee stock plans	(3,942)	(4,456)
Provision for excess and obsolete inventories	317	450
Deferred income taxes	(2,235)	1,307
Changes in operating assets and liabilities:
Accounts receivable, net	(26,132)	(35,028)
Inventories	(13,215)	1,301
Prepaid expenses	5,937	1,015
Other current assets	1,019	1,412
Net investment in sales-type leases	(3,220)	677
Other long-term assets	247	360
Accounts payable	(127)	5,420
Accrued compensation	(5,003)	(6,533)
Accrued liabilities	4,608	(416)
Deferred service revenue	(4,199)	2,650
Deferred gross profit	(1,170)	15,585
Other long-term liabilities	(833)	838
Net cash provided by operating activities	5,932	34,315
Investing Activities
Acquisition of intangible assets, intellectual property and patents	(331)	(236)
Software development for external use	(9,445)	(7,925)
Purchases of property and equipment	(6,081)	(10,151)
Business acquisitions, net of cash acquired	(25,455)	(19,749)
Net cash used in investing activities	(41,312)	(38,061)
Financing Activities
Proceeds from issuances under stock-based compensation plans	15,665	18,157
Employees' taxes paid related to restricted stock units	(2,285)	(2,023)
Common stock repurchases	(50,021)	(17,052)
Excess tax benefits from employee stock plans	3,942	4,456
Net cash (used) provided by financing activities	(32,699)	3,538
Effect of exchange rate changes on cash and cash equivalents	(52)	(136)
Net decrease in cash and cash equivalents	(68,131)	(344)
Cash and cash equivalents at beginning of period	125,888	104,531
Cash and cash equivalents at end of period	57,757	104,187
Supplemental cash flow information
Cash paid for interest	94	0
Cash paid for taxes, net of refunds	7,027	0
Supplemental disclosing of non-cash investing activities
Unpaid property and equipment purchases	554	444
Non-cash activity business acquisition	7,386	860
Treasury stock in accrued liabilities	$ 0	$ 2,586