Change in Accounting for Retirement-Related Benefits (Tables)
 3 Months Ended
Apr. 30, 2016
Change in Accounting for Retirement-Related Benefits [Abstract]  
Schedule of Prior Period Adjustments Made to Consolidated Statements of Operations [Table Text Block]
Consolidated Statements of Operations
 
Three Months Ended
 
May 2, 2015
($ in millions, except per share data)
Previously Reported
 
As Adjusted
 
Effect of Change
Pension
$
10

 
$
(19
)
 
$
(29
)
Income/(loss) before income taxes
(173
)
 
(144
)
 
29

Income tax expense/(benefit)
(6
)
 
6

 
12

Net income/(loss)
$
(167
)
 
(150
)
 
$
17

Basic earnings/(loss) per common share
$
(0.55
)
 
$
(0.49
)
 
$
0.06

Diluted earnings/(loss) per common share
$
(0.55
)
 
$
(0.49
)
 
$
0.06
Schedule of Prior Period Adjustments Made to Consolidated Statements of Comprehensive Income/(Loss) [Table Text Block]
Consolidated Statements of Comprehensive Income/(Loss)
 
Three Months Ended
 
May 2, 2015
($ in millions)
Previously Reported
 
As Adjusted
 
Effect of Change
Net income/(loss)
$
(167
)
 
$
(150
)
 
$
17

Reclassifications for amortization of net actuarial (gain)/loss
17

 
—

 
(17
)
Total other comprehensive income/(loss), net of tax
17

 
—

 
(17
)
Total comprehensive income/(loss), net of tax
$
(150
)
 
$
(150
)
 
$
—
Schedule of Prior Period Adjustments Made to Consolidated Balance Sheet [Table Text Block]
Consolidated Balance Sheets
 
May 2, 2015
($ in millions)
Previously Reported
 
As Adjusted
 
Effect of Change
Reinvested earnings/(accumulated deficit)
$
(1,946
)
 
$
(2,644
)
 
$
(698
)
Accumulated other comprehensive income/(loss)
(1,048
)
 
(350
)
 
698
Schedule of Prior Period Adjustments Made to Consolidated Statements of Cash Flows [Table Text Block]
Consolidated Statements of Cash Flows
 
Three Months Ended
 
May 2, 2015
($ in millions)
Previously Reported
 
As Adjusted
 
Effect of Change
Cash flows from operating activities:
 
 
 
 
 
Net income/(loss)
$
(167
)
 
$
(150
)
 
$
17

Benefit plans
4

 
(25
)
 
(29
)
Deferred taxes
$
(11
)
 
$
1

 
$
12