Employee Benefits - Single-Employer Defined Benefit Pension Plan - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 30, 2017 USD ($) payment	Dec. 31, 2016 USD ($)	Jan. 02, 2016 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Unfunded status		$ 30,360	$ 34,349
Gain (loss) adjustment to other comprehensive income (loss) net of tax		100	(2,100)	$ 400
Decrease in the unfunded obligation		4,000
Actuarial loss		5,808	2,094
Actual return on plan assets		11,109	4,868
Employer contributions		3,674	5,384
Charge due to current year service and interest cost		5,300
Net periodic pension costs		186	(799)	$ (730)
Defined benefit plan, settlement, plan assets			4,300
Estimated net loss expected to be amortized from accumulated other comprehensive loss into net periodic cost over the next fiscal year		1,000
Accumulated benefit obligation for the hourly pension plan		$ 118,200	$ 112,300
Expected return on plan assets assumption (percent)		8.10%	7.82%
Number of minimum quarterly cash contributions during fiscal 2016 and 2017 | payment		4
Minimum required contribution for plan year, per quarter cash contributions during fiscal - 2016		$ 4,300
Scenario, Forecast
Defined Benefit Plan Disclosure [Line Items]
Expected decrease in pension expense in future period	$ 400
Expected return on plan assets assumption (percent)	6.00%