Regulatory Requirements (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Broker Dealer Subsidiaries Net Capital [Line Items]
Minimum percentage of net capital required for broker dealer subsidiary aggregate indebtedness	6.67%	6.67%
Total Net Capital [Abstract]
Total Required Net Capital	$ 226,000,000	$ 226,000,000	$ 210,000,000
Total Net Capital	1,279,000,000	1,279,000,000	1,338,000,000
Total Excess Net Capital	1,053,000,000	1,053,000,000	1,128,000,000
E TRADE Securities [Member]
Broker Dealer Subsidiaries Net Capital [Line Items]
Capital requirement of consolidated broker-dealer subsidiary electing alternative method	$ 250,000	$ 250,000
Minimum percentage of aggregate debit balances to calculate net capital	2.00%	2.00%
Broker-Dealer, Minimum Net Capital Required, Alternative Standard [Abstract]
Broker-Dealer, Minimum Net Capital Required, Alternative Standard	$ 223,000,000	$ 223,000,000	209,000,000
Broker-Dealer, Net Capital	1,251,000,000	1,251,000,000	1,294,000,000
Broker-Dealer, Excess Net Capital, Alternative Standard	$ 1,028,000,000	1,028,000,000	1,085,000,000
Total Net Capital [Abstract]
Dividends from subsidiaries paid to parent company		$ 910,000,000
E TRADE Futures [Member]
Broker Dealer Subsidiaries Net Capital [Line Items]
Minimum percentage of total risk margin requirements to calculate net capital	8.00%	8.00%
Futures Commission Merchant, Commodity Exchange Act, Excess Net Capital [Abstract]
Futures Commission Merchant, Commodity Exchange Act, Required Net Capital	$ 3,000,000	$ 3,000,000	1,000,000
Futures Commission Merchant, Commodity Exchange Act, Adjusted Net Capital	28,000,000	28,000,000	26,000,000
Futures Commission Merchant, Commodity Exchange Act, Excess Net Capital	25,000,000	25,000,000	25,000,000
E TRADE Futures [Member] | Minimum [Member]
Futures Commission Merchant, Commodity Exchange Act, Excess Net Capital [Abstract]
Futures Commission Merchant, Commodity Exchange Act, Required Net Capital	1,000,000	$ 1,000,000
International broker-dealer [Member]
Total Net Capital [Abstract]
Total Required Net Capital			0
Total Net Capital			18,000,000
Total Excess Net Capital			$ 18,000,000
E TRADE Bank [Member]
Total Net Capital [Abstract]
Dividends from subsidiaries paid to parent company	$ 835,000,000