Derivative and Hedging Activities Cumulative Basis Adjustment for Fair Value Hedges (Details) - Designated as Hedging Instrument [Member] $ in Millions	Dec. 31, 2020 USD ($)
Balance Sheet Recording of Fair Value Hedge [Line Items]
Deferred (Gain) Loss on Discontinuation of Fair Value Hedge	$ 3
Underlying Hedged Asset, Amortized Cost Basis	604
Derivative Liability Notional Amount, Terminated	$ 500

Amount as of the balance sheet date of the unamortized adjustment to the carrying value of an interest-bearing hedged item made under an effective fair value hedge that is amortized upon discontinuation of the fair value hedge.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 35
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=121561968&loc=d3e75592-113984

Name:	us-gaap_DeferredGainLossOnDiscontinuationOfFairValueHedge
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant