Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues
Subscription revenue		$ 118,411	$ 101,560	$ 339,772	$ 288,288
Professional services		21,669	18,501	64,543	50,621
Total revenues		140,080	120,061	404,315	338,909
Cost of revenues
Subscription		17,131	16,095	51,277	46,024
Professional services		14,423	13,133	42,811	36,929
Total cost of revenues	[1],[2]	31,554	29,228	94,088	82,953
Gross profit		108,526	90,833	310,227	255,956
Operating costs and expenses:
Research and development	[2]	36,207	28,028	102,028	84,523
Sales and marketing	[1],[2]	31,428	27,789	94,321	80,856
General and administrative	[2]	23,701	20,089	70,772	57,866
Wire transaction recovery	[3]	4,770	0	4,770	0
Total operating costs and expenses		86,566	75,906	262,351	223,245
Operating income		21,960	14,927	47,876	32,711
Interest and other income (expense):
Interest expense		(4,407)	(4,220)	(13,117)	(12,530)
Interest income		1,531	1,005	4,030	2,809
Other income (expense), net		(7)	(7)	(7)	(8)
Total interest and other expense, net		(2,883)	(3,222)	(9,094)	(9,729)
Income before income taxes		19,077	11,705	38,782	22,982
Provision for income taxes		6,233	4,347	8,170	4,839
Net income		$ 12,844	$ 7,358	$ 30,612	$ 18,143
Earnings per share:
Basic		$ 0.23	$ 0.13	$ 0.54	$ 0.33
Diluted		$ 0.21	$ 0.13	$ 0.51	$ 0.32
Weighted average common shares outstanding:
Basic		56,654	55,670	56,389	55,395
Diluted		60,614	57,738	59,664	57,272
Total stock-based compensation	[2]	$ 12,009	$ 10,458	$ 35,022	$ 31,155
Total amortization of intangible assets	[1]	1,213	398	2,891	900
Cost of revenues
Weighted average common shares outstanding:
Total stock-based compensation	[2]	1,152	1,154	3,567	3,603
Total amortization of intangible assets	[1]	1,094	314	2,570	707
Research and development
Weighted average common shares outstanding:
Total stock-based compensation	[2]	3,472	2,292	9,734	6,809
Sales and marketing
Weighted average common shares outstanding:
Total stock-based compensation	[2]	1,864	1,633	4,875	5,349
Total amortization of intangible assets	[1]	119	84	321	193
General and administrative
Weighted average common shares outstanding:
Total stock-based compensation	[2]	$ 5,521	$ 5,379	$ 16,846	$ 15,394

[1] Amortization of intangible assets included in cost of revenues and operating costs and expenses

[2] Stock-based compensation expense included in cost of revenues and operating costs and expenses

[3] Operating costs and expenses for the three and nine months ended September 30, 2017 reflect probable insurance recovery of amounts associated with the previously reported 2014 wire transaction loss. For additional details, see Note 2, "Wire Transaction Recovery."