Stockholders' Equity, ATM Program and 401(k) Matching Contributions (Details) - USD ($)		12 Months Ended
	Feb. 11, 2013	Dec. 31, 2015	Dec. 31, 2014
Stockholders' Equity [Line Items]
Issuance of common stock, 401(k) employer match (in shares)		94,114	42,371
Expense associated with 401(k) plan		$ 500,000	$ 1,000,000
Stifel ATM Program [Member]
Stockholders' Equity [Line Items]
Period of agency agreement	3 years
Maximum value of potential common stock available for issue	$ 25,000,000
Percentage sales commission on shares	3.00%