Annual report pursuant to Section 13 and 15(d)

Available-for-Sale Securities, at Fair Value Schedule of Unrealized Loss on Investments (Details)

v3.3.1.900
Available-for-Sale Securities, at Fair Value Schedule of Unrealized Loss on Investments (Details)
$ in Thousands
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Number of Positions 1,181 1,452
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year 121 57
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year 182 172
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value $ 1,503,939 $ 413,102
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss (26,984) (3,146)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value 1,141,839 1,323,688
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss (44,412) (32,885)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value 2,645,778 1,736,790
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss $ (71,396) $ (36,031)