Segment Information (Summary of Financial Information by Segment) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenue
Hosted services – Business		$ 46,729	$ 50,197	$ 92,688	$ 100,809
Hosted services – Consumer		4,238	3,862	8,004	7,559
Professional services		5,712	5,275	11,452	10,736
Revenue		56,679	59,334	112,144	119,104
Cost of revenue	[1],[2],[3]	17,508	18,052	33,372	34,307
Sales and marketing	[2],[3]	23,088	24,382	45,764	48,676
Amortization of purchased intangibles	[2],[3]	1,017	1,178	1,941	2,490
Unallocated corporate expenses		20,880	23,403	39,623	43,367
Operating income (loss)		(5,814)	(7,681)	(8,556)	(9,736)
Business [Member]
Revenue
Hosted services – Business		46,729	50,197	92,688	100,809
Professional services		5,712	5,275	11,452	10,736
Revenue		52,441	55,472	104,140	111,545
Cost of revenue		16,691	17,436	31,929	33,053
Sales and marketing		21,315	22,617	42,328	45,531
Amortization of purchased intangibles		1,017	1,178	1,941	2,490
Operating income (loss)		13,418	14,241	27,942	30,471
Consumer [Member]
Revenue
Hosted services – Consumer		4,238	3,862	8,004	7,559
Revenue		4,238	3,862	8,004	7,559
Cost of revenue		817	616	1,443	1,254
Sales and marketing		1,773	1,765	3,436	3,145
Operating income (loss)		1,648	1,481	3,125	3,160
Corporate [Member]
Revenue
Unallocated corporate expenses		20,880	23,403	39,623	43,367
Operating income (loss)		$ (20,880)	$ (23,403)	$ (39,623)	$ (43,367)

[1] Amounts include amortization expense as follows: Cost of revenue $697 thousand and $839 thousand for the three months ended June 30, 2016 and 2015, respectively.Amounts include amortization expense as follows: Cost of revenue $1,394 thousand and $1,679 thousand for the three months ended June 30, 2016 and 2015, respectively.

[2] Amounts include depreciation expense as follows: Cost of revenue $2,374 thousand and $2,323 thousand for the three months ended June 30, 2016 and 2015, respectively, Sales and marketing $521 thousand and $314 thousand for the three months ended June 30, 2016 and 2015, respectively, General and administrative $382 thousand and $236 thousand for the three months ended June 30, 2016 and 2015, respectively, and Product development $351 thousand and $209 thousand for the three months ended June 30, 2016 and 2015, respectively. Amounts include depreciation expense as follows: Cost of revenue $4,712 thousand and $4,225 thousand for the three months ended June 30, 2016 and 2015, respectively, Sales and marketing $800 thousand and $565 thousand for the three months ended June 30, 2016 and 2015, respectively, General and administrative $780 thousand and $473 thousand for the three months ended June 30, 2016 and 2015, respectively, and Product development $502 thousand and $397 thousand for the three months ended June 30, 2016 and 2015, respectively.

[3] Amounts include stock compensation expense as follows: Cost of revenue $211 thousand and $476 thousand for the three months ended June 30, 2016 and 2015, respectively, Sales and marketing $804 thousand and $937 thousand for the three months ended June 30, 2016 and 2015, respectively, General and administrative $941 thousand and $746 thousand for the three months ended June 30, 2016 and 2015, respectively and Product development $1,070 thousand and $953 thousand for the three months ended June 30, 2016 and 2015, respectively. Amounts include stock compensation expense as follows: Cost of revenue $221 thousand and $804 thousand for the six months ended June 30, 2016 and 2015, respectively, Sales and marketing $1,434 thousand and $1,532 thousand for the six months ended June 30, 2016 and 2015, respectively, General and administrative $1,793 thousand and $1,678 thousand for the six months ended June 30, 2016 and 2015, respectively and Product development $1,897 thousand and $1,892 thousand for the six months ended June 30, 2016 and 2015, respectively.