XML 64 R52.htm IDEA: XBRL DOCUMENT v3.19.2
Associate Retirement Plans - Additional Information (Detail) - USD ($)
 3 Months Ended 6 Months Ended
Feb. 28, 2018
Jul. 13, 2019
Jul. 14, 2018
Jul. 13, 2019
Jul. 14, 2018
Defined Benefit Plan Disclosure [Line Items]          
Pension contributions during last plan year   $ 3,400,000 $ 3,400,000 $ 8,200,000 $ 7,900,000
Pension Plan or Plan [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Frozen pension plan, termination date       Jul. 31, 2018  
Settlement and other termination expenses, recognized       $ 8,900,000  
Standard pension funding carryover       0  
Pension Plan or Plan [Member] | Minimum [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Pre-tax settlement charges $ 19,000,000        
Pension Plan or Plan [Member] | Maximum [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Pre-tax settlement charges $ 20,000,000        
Retiree Medical Plan [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Standard pension funding carryover       200,000  
Expected Company contribution for remainder of fiscal year   400,000   400,000  
SpartanNash Company Pension Plan [Member] | Pension Plan or Plan [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Net periodic benefit (income) expense   8,800,000 (100,000) 9,200,000 (200,000)
SpartanNash Retiree Medical Plan [Member] | Retiree Medical Plan [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Net periodic benefit (income) expense   $ 100,000 $ 100,000 $ 200,000 $ 200,000