Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue:
Software license	$ 84,996	$ 78,615	$ 71,583
Services	467,286	428,078	376,023
Hardware and other	52,275	49,678	44,498
Total revenue	604,557	556,371	492,104
Costs and expenses:
Cost of license	10,820	9,938	7,110
Cost of services	197,475	184,349	169,140
Cost of hardware and other	41,584	41,141	36,328
Research and development	54,736	53,859	48,953
Sales and marketing	48,223	48,615	52,617
General and administrative	48,322	49,259	44,455
Depreciation and amortization	9,090	7,764	6,377
Total costs and expenses	410,250	394,925	364,980
Operating income	194,307	161,446	127,124
Interest income	1,161	1,331	1,268
Other income (loss), net	639	64	(394)
Income before income taxes	196,107	162,841	127,998
Income tax provision	71,873	59,366	45,998
Net income	$ 124,234	$ 103,475	$ 82,000
Basic earnings per share	$ 1.73	$ 1.41	$ 1.09
Diluted earnings per share	$ 1.72	$ 1.40	$ 1.08
Weighted average number of shares:
Basic	71,674	73,443	74,995
Diluted	72,060	74,038	75,841