Pledged Assets Repurchase Agreements with Counterparties Greater than or Equal to 5% of Equity at Risk (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) days	Dec. 31, 2017 USD ($) days
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Line Items]
Document Period End Date	Dec. 31, 2018
Securities Sold under Agreements to Repurchase | $	$ 75,717	$ 50,296
Risk Of Repurchase Agreement To Stockholders Equity	4.00%
Weighted Average Days to Maturity | days	49	116
FICC [Member]
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Line Items]
Risk Of Repurchase Agreement To Stockholders Equity	8.00%