Fair Value Accounting - Carrying Values and Fair Values of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Restricted cash	$ 597	$ 597
Marketable securities	39,590	3,728
Senior notes	85,518	83,867
Note payable to related party	0	3,863
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Restricted cash	428	369
Marketable securities	39,590	3,728
Senior notes	15,017	13,119
Note payable to related party	$ 0	$ 2,880