Organization and Significant Accounting Policies - Certain Significant Risks and Uncertainties (Details)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Gross accounts receivable | One Customer      
Certain Significant Risks and Uncertainties      
Concentration risk (as a percent) 0.00% 0.00% 35.00%