Common Stock and Other Equity Related Transactions - Employee Stock Purchase Program (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Stock Purchase Program [Line Items]
ESPP, purchase price discount (in percentage)	85.00%
ESPP, issued during the period (in shares)	17,037	19,788	30,739
Employee Stock Purchase Plan
Employee Stock Purchase Program [Line Items]
Amendment Date	May 10, 2016
Maximum
Employee Stock Purchase Program [Line Items]
ESPP authorized amount	$ 250,000
Number of shares authorized ESPP (in shares)	2,000,000