Segment Information (Summary of Financial Information by Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Revenue
Hosted services – Business	$ 41,996		$ 36,634		$ 81,677		$ 72,778
Hosted services – Consumer	4,539		3,776		8,448		7,395
Professional services	4,552		2,819		8,790		5,552
Revenue	51,087		43,229		98,915		85,725
Cost of revenue	13,161	[1],[2]	10,612	[1],[2]	24,896	[1],[2]	20,746	[1],[2]
Sales and marketing	20,077	[1],[2]	15,499	[1],[2]	38,472	[1],[2]	29,977	[1],[2]
Amortization of purchased intangibles	206		224		396		448
Unallocated corporate expenses	19,124		18,882		37,573		37,140
Operating income (loss)	(1,481)		(1,988)		(2,422)		(2,586)
Business [Member]
Revenue
Hosted services – Business	41,996		36,634		81,677		72,778
Professional services	4,552		2,819		8,790		5,552
Revenue	46,548		39,453		90,467		78,330
Cost of revenue	12,483		9,974		23,627		19,510
Sales and marketing	18,799		14,243		35,717		27,449
Amortization of purchased intangibles	206		224		396		448
Operating income (loss)	15,060		15,012		30,727		30,923
Consumer [Member]
Revenue
Hosted services – Consumer	4,539		3,776		8,448		7,395
Revenue	4,539		3,776		8,448		7,395
Cost of revenue	678		638		1,269		1,236
Sales and marketing	1,278		1,256		2,755		2,528
Operating income (loss)	2,583		1,882		4,424		3,631
Corporate [Member]
Revenue
Unallocated corporate expenses	19,124		18,882		37,573		37,140
Operating income (loss)	$ (19,124)		$ (18,882)		$ (37,573)		$ (37,140)

[1] Amounts include stock compensation expense as follows: Cost of revenue $484 and $501 for the three months ended June 30, 2014 and 2013, respectively and $844 and $922 for the six months ended June 30, 2014 and 2013, respectively, Sales and marketing $923 and $569 for the three months ended June 30, 2014 and 2013, respectively and $1,737 and $1,315 for the six months ended June 30, 2014 and 2013, respectively, General and administrative $869 and $1,019 for the three months ended June 30, 2014 and 2013, respectively and $1,712 and $2,034 for the six months ended June 30, 2014 and 2013, respectively, and Product development $931 and $812 for the three months ended June 30, 2014 and 2013, respectively and $1,611 and $1,681 for the six months ended June 30, 2014 and 2013, respectively.

[2] Amounts include depreciation expense as follows: Cost of revenue $1,646 and $1,540 for the three months ended June 30, 2014 and 2013, respectively and $3,044 and $3,120 for the six months ended June 30, 2014 and 2013, respectively, Sales and marketing $201 and $22 for the three months ended June 30, 2014 and 2013, respectively and $408 and $45 for the six months ended June 30, 2014 and 2013, respectively, General and administrative $214 and $261 for the three months ended June 30, 2014 and 2013, respectively and $414 and $523 for the six months ended June 30, 2014 and 2013, respectively, and Product development $172 and $175 for the three months ended June 30, 2014 and 2013, respectively and $349 and $360 for the six months ended June 30, 2014 and 2013, respectively.