Stockholders' Equity, Restricted Stock Units (Details) - USD ($) $ / shares in Units, $ in Thousands			6 Months Ended	12 Months Ended
	May 27, 2015	Apr. 21, 2015	Jun. 30, 2016	Dec. 31, 2015
Restricted Stock Units ("RSUs") [Member]
Restricted stock units, number of shares [Roll Forward]
Outstanding RSUs, beginning of period (in shares)			1,697,897
Awarded (in shares)			261,215
Released (in shares)			(403,064)
Forfeited (in shares)			(318,504)
Outstanding RSUs, end of period (in shares)			1,237,544	1,697,897
Restricted stock units, weighted average grant-date fair value [Roll forward]
Outstanding RSUs, beginning of period (in dollars per share)			$ 2.25
Awarded (in dollars per share)			0.89
Released (in dollars per share)			1.73
Forfeited (in dollars per share)			2.00
Outstanding RSUs, end of period (in dollars per share)			$ 2.20	$ 2.25
Restricted stock units, additional disclosures [Abstract]
Outstanding RSUs, weighted average remaining contractual term			1 year 5 months 19 days	1 year 4 months 28 days
Outstanding RSUs, aggregate intrinsic value			$ 1,041	$ 1,715
Compensation cost not yet recognized [Abstract]
Unrecognized compensation cost related to restricted stock units			$ 1,800
Weighted average period of recognition for unrecognized compensation cost			2 years 4 months 24 days
May 27, 2015 Award [Member] | Time-based RSUs [Member] | Non-employee Directors [Member]
Restricted stock units, number of shares [Roll Forward]
Awarded (in shares)	173,610
April 21, 2015 Award [Member] | Time-based RSUs [Member] | Corporate Employees [Member]
Restricted stock units, number of shares [Roll Forward]
Awarded (in shares)		397,000
Compensation cost not yet recognized [Abstract]
Vesting period			3 years