Investment Operations Variable Interest Entities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	$ 105,998	$ 103,701
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	160,274	151,341
Low income housing tax credits
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	48,250	54,037
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	49,752	55,597
Investment companies
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	47,840	40,236
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	94,091	79,578
Real estate limited partnerships
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	9,415	8,945
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	15,938	15,673
Other VIE investments
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	493	483
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	$ 493	$ 493