Investment Securities (Details 2) $ in Millions	Mar. 31, 2021 USD ($) security	Dec. 31, 2020 security
Number of Securities
Less than 12 months | security	10
12 months or more | security	0
Total | security	10	0
Estimated Fair Value
Less than 12 months	$ 35
12 months or more	0
Total	35
Gross Unrealized Losses
Less than 12 months	(1)
12 months or more	0
Total	$ (1)
90%-100%
Number of Securities
Less than 12 months | security	9
12 months or more | security	0
Total | security	9
Estimated Fair Value
Less than 12 months	$ 34
12 months or more	0
Total	34
Gross Unrealized Losses
Less than 12 months	(1)
12 months or more	0
Total	$ (1)
Less than 90%
Number of Securities
Less than 12 months | security	1
12 months or more | security	0
Total | security	1
Estimated Fair Value
Less than 12 months	$ 1
12 months or more	0
Total	1
Gross Unrealized Losses
Less than 12 months	0
12 months or more	0
Total	$ 0