Summary of Investments - SOI Fixed Maturity AFS aging (Details 2) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Amortized cost
Maturing in one year or less	$ 654,368
Maturing after one year through five years	3,780,675
Maturing after five years through ten years	6,312,627
Maturing after ten years	5,138,873
Mortgage-backed and asset-backed securities	3,569,344
Amortized cost	19,455,887	$ 20,007,462
Estimated fair value
Maturing in one year or less	680,991
Maturing after one year through five years	4,030,915
Maturing after five years through ten years	6,719,852
Maturing after ten years	5,613,359
Mortgage-backed and asset-backed securities	3,781,024
Estimated fair value	$ 20,826,141	$ 20,531,627