Annual report pursuant to Section 13 and 15(d)

Retirement Plans and Related Post Retirement Benefits (Detail)

v3.3.1.900
Retirement Plans and Related Post Retirement Benefits (Detail)
 12 Months Ended
Jan. 01, 2014
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
USD ($)
retirement_plan
Dec. 31, 2014
USD ($)
Defined Benefit Plan Disclosure          
Number of non-qualified supplemental retirement defined benefit plans | retirement_plan       2  
Accumulated benefit obligation of the plans       $ 16,700,000 $ 16,500,000
Fair value of plan assets at period end       0 0
Unrecognized prior service costs       2,800,000  
Unrecognized prior service costs, net       4,300,000  
Unrecognized prior service costs, tax       1,500,000  
Unrecognized actuarial losses       4,000,000  
Unrecognized actuarial losses, net       6,100,000  
Unrecognized actuarial losses, net of taxes       2,100,000  
Net periodic pension cost       300,000  
Net periodic pension cost net of tax       400,000  
Net periodic pension cost, tax       100,000  
Defined benefit plan amortization of net gains losses       200,000  
Defined benefit plan amortization of net gains losses,Net       300,000  
Defined benefit plan amortization of net gains losses net of taxes       100,000  
Current accrued pension liability       300,000  
Long-term accrued pension liability       20,100,000  
Expected future payments in 2016       300,000  
Expected future payments in 2017       300,000  
Expected future payments in 2018       300,000  
Expected future payments in 2019       300,000  
Expected future payments in 2020       300,000  
Benefits to be paid in each of the following five years       2,100,000  
Percentage of fund 91.80%        
Contributions of employer       $ 1,000,000 $ 900,000
Total employer contribution       1.00%  
Forecast          
Defined Benefit Plan Disclosure          
Annual increase in the cost of health care benefits   5.50% 5.20%    
Minimum          
Defined Benefit Plan Disclosure          
Annual increase in the cost of health care benefits range       3.80%  
Maximum          
Defined Benefit Plan Disclosure          
Annual increase in the cost of health care benefits range       6.40%  
SERP          
Defined Benefit Plan Disclosure          
Unrecognized prior service costs       $ 100,000  
Unrecognized actuarial losses       200,000  
Unrecognized actuarial losses, net of taxes       200,000  
Current accrued pension liability       100,000  
Long-term accrued pension liability       900,000  
Benefits to be paid in each of the following five years       300,000  
Change in retirement benefit obligation       100,000  
SERP | Minimum          
Defined Benefit Plan Disclosure          
Expected future payments in 2020       $ 100,000