Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Concentration of Credit Risk (Details)

v3.3.1.900
Summary of Significant Accounting Policies - Concentration of Credit Risk (Details) - Consolidated Gross Revenues [Member]
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Concentration Risk [Line Items]      
Concentration risk, customer 0 0 0
Concentration risk, percentage 10.00% 10.00% 10.00%