Restructuring Costs (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring costs	[1],[2]	$ 2,988	$ 0	$ 2,988	$ 0
Restructuring liability		1,716		1,716
Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs				1,745
Restructuring liability		644		644
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs				1,243
Restructuring liability		1,072		1,072
Accrued Expenses And Other Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring liability		$ 1,716		$ 1,716

[1] Amounts include depreciation expense as follows: Cost of revenue $2,323 and $1,646 for the three months ended June 30, 2015 and 2014, respectively and $4,225 and $3,044 for the six months ended June 30, 2015 and 2014, respectively, Sales and marketing $314 and $201 for the three months ended June 30, 2015 and 2014, respectively and $565 and $408 for the six months ended June 30, 2015 and 2014, respectively, Product development $209 and $172 for the three months ended June 30, 2015 and 2014, respectively and $397 and $349 for the six months ended June 30, 2015 and 2014, respectively, and General and administrative $236 and $214 for the three months ended June 30, 2015 and 2014, respectively and $473 and $414 for the six months ended June 30, 2015 and 2014, respectively.

[2] Amounts include stock compensation expense as follows: Cost of revenue $476 and $484 for the three months ended June 30, 2015 and 2014, respectively and $804 and $844 for the six months ended June 30, 2015 and 2014, respectively, Sales and marketing $1,937 and $923 for the three months ended June 30, 2015 and 2014, respectively and $1,532 and $1,737 for the six months ended June 30, 2015 and 2014, respectively, Product development $953 and $931 for the three months ended June 30, 2015 and 2014, respectively and $1,892 and $1,611 for the six months ended June 30, 2015 and 2014, respectively, and General and administrative $746 and $869 for the three months ended June 30, 2015 and 2014, respectively and $1,678 and $1,712 for the six months ended June 30, 2015 and 2014, respectively.