Intangible Assets - Future Amortization Expense (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Intangible Assets
Intangible assets acquired			$ 365,000
Amortization expense
Amortization expense	1,000,000	1,100,000	3,200,000	3,300,000
Amortization expense for each of the five years through December 31, 2018 and thereafter
Three months ending December 31, 2014	1,036,000		1,036,000
2015	4,134,000		4,134,000
2016	4,041,000		4,041,000
2017	3,862,000		3,862,000
2018	3,861,000		3,861,000
Thereafter	12,050,000		12,050,000
Total amortization expense	28,984,000		28,984,000		31,834,000
Domain name
Intangible Assets
Intangible assets acquired			$ 400,000