ESOP Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Class of Stock [Line Items]
Additional paid-in capital included related to ESOP preferred stock	$ 37	$ 37
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Shares issued and outstanding	609,434	609,434
Carrying value	$ 609	$ 609
Unearned ESOP shares	$ (646)	$ (646)
Employee Stock Ownership Plan Preferred Stock 2018 [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Shares issued and outstanding	189,225	189,225
Carrying value	$ 189	$ 189
Employee Stock Ownership Plan Preferred Stock 2018 [Member] | Minimum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	7.00%	7.00%
Employee Stock Ownership Plan Preferred Stock 2018 [Member] | Maximum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	8.00%	8.00%
Employee Stock Ownership Plan Preferred Stock 2017 [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Shares issued and outstanding	135,135	135,135
Carrying value	$ 135	$ 135
Employee Stock Ownership Plan Preferred Stock 2017 [Member] | Minimum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	7.00%	7.00%
Employee Stock Ownership Plan Preferred Stock 2017 [Member] | Maximum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	8.00%	8.00%
Employee Stock Ownership Plan Preferred Stock 2016 [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Shares issued and outstanding	128,380	128,380
Carrying value	$ 128	$ 128
Employee Stock Ownership Plan Preferred Stock 2016 [Member] | Minimum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	9.30%	9.30%
Employee Stock Ownership Plan Preferred Stock 2016 [Member] | Maximum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	10.30%	10.30%
Employee Stock Ownership Plan Preferred Stock 2015 [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Shares issued and outstanding	68,106	68,106
Carrying value	$ 68	$ 68
Employee Stock Ownership Plan Preferred Stock 2015 [Member] | Minimum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	8.90%	8.90%
Employee Stock Ownership Plan Preferred Stock 2015 [Member] | Maximum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	9.90%	9.90%
Employee Stock Ownership Plan Preferred Stock 2014 [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Shares issued and outstanding	62,420	62,420
Carrying value	$ 63	$ 63
Employee Stock Ownership Plan Preferred Stock 2014 [Member] | Minimum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	8.70%	8.70%
Employee Stock Ownership Plan Preferred Stock 2014 [Member] | Maximum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	9.70%	9.70%
Employee Stock Ownership Plan Preferred Stock 2013 [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Shares issued and outstanding	26,168	26,168
Carrying value	$ 26	$ 26
Employee Stock Ownership Plan Preferred Stock 2013 [Member] | Minimum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	8.50%	8.50%
Employee Stock Ownership Plan Preferred Stock 2013 [Member] | Maximum [Member]
Detail of Employee Stock Ownership Plan Preferred Stock [Abstract]
Adjustable dividend rate	9.50%	9.50%
Equity award [Member] | Convertible preferred stock [Member] | Minimum [Member]
Class of Stock [Line Items]
Preferred stock, redemption price per share	$ 1,000	$ 1,000