Policyholders' Liabilities (Future Policy Benefits) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life insurance – domestic	$ 964	$ 75
Individual and group annuities and supplementary contracts	446,318	441,595
Other contract liabilities	1,267,739	3,136,992
Total future policy benefits	8,686,196	3,578,662
Assumed | Pruco Life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Individual and group annuities and supplementary contracts	528,210	0
Other contract liabilities	$ 6,442,965	$ 0