Retirement and Other Benefit Plans (Tables)
 3 Months Ended
Apr. 29, 2017
Compensation and Retirement Disclosure [Abstract]  
Schedule of Components of Net Periodic Benefit Cost (Income)
The following table sets forth the components of net periodic benefit cost (income) for the Company, including domestic and Canadian plans:
 
Pension Benefits
Other Postretirement Benefits
 
Thirteen Weeks Ended
Thirteen Weeks Ended
($ thousands)
April 29, 2017

April 30, 2016

April 29, 2017

April 30, 2016

Service cost
$
2,467

$
2,263

$
—

$
—

Interest cost
3,747

3,861

18

15

Expected return on assets
(6,880
)
(7,223
)
—

—

Amortization of:
 

 

 

 

Actuarial loss (gain)
1,152

38

(38
)
(55
)
Prior service income
(435
)
(460
)
—

—

Total net periodic benefit cost (income)
$
51

$
(1,521
)
$
(20
)
$
(40
)