Stockholders' Equity (Tables)
 12 Months Ended
Jan. 31, 2015
Stockholders' Equity Note [Abstract]  
Schedule Of Reclassifications Out Of Accumulated Other Comprehensive Income [Table Text Block]
 
Amount Reclassified from Accumulated Other Comprehensive Income/(Loss)
 
Line Item in the Consolidated Statements of Operations
 
 
($ in millions)
2014
 
2013
 
2012
 
Realized (gain)/loss on REITs
 
 
 
 
 
 
 
Sale or redemption of SPG REIT units
$
—

 
$
(24
)
 
$
(270
)
 
Real estate and other, net
Sale of CBL REIT shares
—

 
—

 
(15
)
 
Real estate and other, net
Tax (expense)/benefit
—

 
8

 
101

 
Income tax expense/(benefit)
Total, net of tax
—

 
(16
)
 
(184
)
 
 
Retirement benefit plans
 
 
 
 
 
 
 
Amortization of actuarial (gain)/loss(1)
66

 
176

 
243

 
Pension
Amortization of prior service (credit)/cost(1)
7

 
7

 
1

 
Pension
Amortization of actuarial (gain)/loss(1)
(1
)
 
(1
)
 
(1
)
 
SG&A
Amortization of prior service (credit)/cost(1)
(8
)
 
(8
)
 
(14
)
 
SG&A
Prior service (credit)/cost from a curtailment
—

 
—

 
(5
)
 
Restructuring and management transition (Note 15)
Actuarial (gain)/loss from a settlement(1)
—

 
—

 
148

 
Pension
Tax (expense)/benefit
(25
)
 
(67
)
 
(144
)
 
Income tax expense/(benefit)
Decrease in deferred tax valuation allowance
25

 
—

 
—

 
Income tax expense/(benefit)
Total, net of tax
64

 
107

 
228

 
 
Total reclassifications
$
64

 
$
91

 
$
44

 
 

(1)
These accumulated other comprehensive components are included in the computation of net periodic benefits expense/(income). See Note 14 for additional details.
Schedule of Comprehensive Income/(Loss)
 
2014
 
2013
 
2012
($ in millions)
Gross Amount
 
Income Tax (Expense)/Benefit(1)
 
Net Amount
 
Gross Amount
 
Income Tax (Expense)/Benefit(2)
 
Net Amount
 
Gross Amount
 
Income Tax (Expense)/Benefit(3)
 
Net Amount
REITs
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Unrealized gain/(loss)
$
—

 
$
—

 
$
—

 
$
(2
)
 
$
1

 
$
(1
)
 
$
56

 
$
(20
)
 
$
36

Reclassification adjustment for (gain)/loss
—

 
—

 
—

 
(24
)
 
8

 
(16
)
 
(285
)
(4) 
101

 
(184
)
Foreign currency
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Unrealized gain/(loss)
(2
)
 
—

 
(2
)
 
—

 
—

 
—

 
—

 
—

 
—

Retirement benefit plans
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Net actuarial gain/(loss) arising during the period
(479
)
 
186

 
(293
)
 
659

 
(255
)
 
404

 
60

 
(23
)
 
37

Prior service credit/(cost) arising during the period
(20
)
 
8

 
(12
)
 
(7
)
 
3

 
(4
)
 
(42
)
 
16

 
(26
)
Reclassification of net prior service (credit)/cost from a curtailment
—

 
—

 
—

 
—

 
—

 
—

 
(5
)
 
2

 
(3
)
Reclassification of net actuarial (gain)/loss from a settlement
—

 
—

 
—

 
—

 
—

 
—

 
148

 
(57
)
 
91

Reclassification for amortization of net actuarial (gain)/loss
65

 
(25
)
 
40

 
175

 
(67
)
 
108

 
242

 
(94
)
 
148

Reclassification for amortization of prior service (credit)/cost
(1
)
 
—

 
(1
)
 
(1
)
 
—

 
(1
)
 
(13
)
 
5

 
(8
)
Deferred tax valuation allowance
—

 
(169
)
 
(169
)
 
—

 
—

 
—

 
—

 
—

 
—

Total
$
(437
)
 
$
—

 
$
(437
)
 
$
800

 
$
(310
)
 
$
490

 
$
161

 
$
(70
)
 
$
91

 
(1)
When we have a loss in operations and a loss in other comprehensive income/(loss), the tax benefits associated with each loss are fully offset by a valuation allowance (Note 17).
(2)
When assessing valuation allowance needs, accounting standards require us to record in other comprehensive income/(loss) the tax expense on other comprehensive income and a corresponding tax benefit in operations (Note 17).
(3)
In accordance with accounting standards, we are required to allocate a portion of our tax provision between operating income/(loss) and other comprehensive income/(loss).
(4)
During the second quarter of 2012, the reclassification adjustment for the Simon Property Group, L.P. (SPG) units of $270 million was calculated by using the closing fair market value per SPG unit of $158.13 on July 19, 2012 for the two million REIT units that were redeemed on July 20, 2012.  The REIT units were redeemed at a price of $124.00 per unit (Note 16). 
Schedule of Accumulated Other Comprehensive Income/(Loss)
($ in millions)
 
Unrealized Gain/(Loss) on REITs
 
Net Actuarial Gain/(Loss)
 
Prior Service Credit/(Cost)
 
Foreign Currency Translation
 
Accumulated Other Comprehensive Income/(Loss)
February 2, 2013
 
$
17

 
$
(1,121
)
 
$
(14
)
 
$
—

 
$
(1,118
)
Current period change
 
(17
)
 
512

 
(5
)
 
—

 
490

February 1, 2014
 
$
—

 
$
(609
)
 
$
(19
)
 
$
—

 
$
(628
)
Current period change
 
—

 
(414
)
 
(21
)
 
(2
)
 
(437
)
January 31, 2015
 
$
—

 
$
(1,023
)
 
$
(40
)
 
$
(2
)
 
$
(1,065
)