Quarterly report pursuant to Section 13 or 15(d)

Available-for-Sale Securities, at Fair Value Schedule of Realized Gain (Loss) (Details)

v3.7.0.1
Available-for-Sale Securities, at Fair Value Schedule of Realized Gain (Loss) (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds $ 2,414,675 $ 2,270,454
Available-for-sale Securities, Gross Realized Gains (Losses), Amortized Cost Sold 2,465,078 2,248,753
Available-for-sale Securities, Gross Realized Gains 8,731 35,194
Available-for-sale Securities, Gross Realized Losses (59,134) (13,493)
Available-for-sale Securities, Gross Realized Gain (Loss) $ (50,403) $ 21,701