Annual report pursuant to Section 13 and 15(d)

Variable Interest Entities (Equity Method Investment) (Details)

v3.6.0.2
Variable Interest Entities (Equity Method Investment) (Details) - USD ($)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Jun. 30, 2015
Schedule of Equity Method Investments [Line Items]        
Impairment of equity method investment $ 0 $ 12,593,000 $ 0  
Next Generation Carrier-Class Communications Services Firm [Member]        
Schedule of Equity Method Investments [Line Items]        
Ownership percentage 40.80%      
Fair value of equity investment       $ 0