Income Taxes (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($) state	Jun. 30, 2014 USD ($) state	Jun. 30, 2015 USD ($) state	Jun. 30, 2014 USD ($) state	Dec. 31, 2014 USD ($)
Number Of States Owed A Tax Liability | state	1	1	1	1
Income tax expense	$ 5	$ 5	$ 10	$ 10
Interest and penalty payments	$ 0	$ 0	$ 0	$ 0
Internal Revenue Service (IRS) [Member]
Operating loss carryforwards, subject to expiration					$ 159,600
State and Local Jurisdiction [Member]
Operating loss carryforwards, subject to expiration					$ 143,900