Other-Than-Temporary Impairment Projected Home Prices Recoveries (Details)	Dec. 31, 2019
Schedule of Held-to-maturity Securities [Line Items]
OTTI Governance Committee projected housing price decline rate over 12-month period	4.00%
OTTI Governance Committee projected housing price increase rate over 12-month period	8.00%
Minimum [Member]
Schedule of Held-to-maturity Securities [Line Items]
Projected short-term house price change - increase rate for majority of markets	2.00%
Maximum [Member]
Schedule of Held-to-maturity Securities [Line Items]
Projected short-term house price change - increase rate for majority of markets	6.00%