Segment Information (Summary of Financial Information by Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Revenue
Hosted services – Business	$ 39,680		$ 36,144
Hosted services – Consumer	3,910		3,620
Professional services	4,238		2,732
Total revenue	47,828		42,496
Cost of revenue	11,735	[1],[2]	10,134	[1],[2]
Sales and marketing	18,395	[1],[2]	14,478	[1],[2]
Amortization of purchased intangibles	190		224
Unallocated corporate expenses	18,450		18,259
Operating income (loss)	(942)		(599)
Corporate [Member]
Revenue
Unallocated corporate expenses	18,450		18,259
Operating income (loss)	(18,450)		(18,259)
Business [Member]
Revenue
Hosted services – Business	39,680		36,144
Professional services	4,238		2,732
Total revenue	43,918		38,876
Cost of revenue	11,220		9,536
Sales and marketing	16,918		13,206
Amortization of purchased intangibles	190		224
Operating income (loss)	15,590		15,910
Consumer [Member]
Revenue
Hosted services – Consumer	3,910		3,620
Total revenue	3,910		3,620
Cost of revenue	515		598
Sales and marketing	1,477		1,272
Operating income (loss)	$ 1,918		$ 1,750

[1] Amounts include stock compensation expense as follows: Cost of revenue $360 and $420, Sales and marketing $814 and $746, General and administrative $843 and $1,015, and Product development $680 and $870 as of March 31, 2014 and March 31, 2013, respectively.

[2] Amounts include depreciation expense as follows: Cost of revenue $1,397 and $1,580, Sales and marketing $207 and $22, General and administrative $200 and $262, and Product development $177 and $186 as of March 31, 2014 and March 31, 2013, respectively.