Stockholders' Equity, Employee Stock Purchase Plan (Details) - Employee Stock Purchase Plan ("ESPP") [Member] - shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Jun. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for issuance (in shares)			333,333
Term for employee stock purchase plan	10 years
Offering period of employee stock purchase plan	6 months
Minimum percentage of fair market value of the specified conditions used to determine purchase price of ESPP			85.00%
Employee stock purchase plan, shares purchased (in shares)	0	0