Other Borrowings (Details)	3 Months Ended
	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Nov. 30, 2014 USD ($)
Line of Credit Facility [Line Items]
Other borrowings	$ 409,000,000	$ 491,000,000
E TRADE Clearing [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	995,000,000
Line of Credit Facility, Fair Value of Amount Outstanding	0
Trust preferred securities
Line of Credit Facility [Line Items]
Other borrowings	$ 409,000,000	409,000,000
Debt instrument maturity year	2031
Repurchase agreements
Line of Credit Facility [Line Items]
Other borrowings	$ 0	82,000,000
Securities Sold Under Agreements To Repurchase Maximum Month end Outstanding Amount		$ 3,800,000,000
Secured Committed Line of Credit [Member] | E TRADE Clearing [Member]
Line of Credit Facility [Line Items]
Lines of Credit. Number of Creditors	2
Secured Committed Line of Credit [Member] | E TRADE Clearing [Member] | Line of Credit, Maturing June 2016 [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 175,000,000
Secured Uncommitted Line of Credit [Member] | E TRADE Clearing [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 375,000,000
Unsecured Uncommitted Line of Credit Member [Member] | E TRADE Clearing [Member]
Line of Credit Facility [Line Items]
Lines of Credit. Number of Creditors	2
Line of Credit Facility, Maximum Borrowing Capacity	$ 100,000,000
Unsecured Uncommitted Line of Credit Member [Member] | E TRADE Clearing [Member] | Line of Credit, Maturing August 2016 [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	75,000,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	250,000,000		$ 200,000,000
Line of Credit Facility, Fair Value of Amount Outstanding	0
Revolving Credit Facility [Member] | E TRADE Clearing [Member] | Revolving Credit Facility, Maturing June 2016 [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 345,000,000