CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 29, 2019
Cash flows from operating activities:
Net loss	$ (549,885,000)	$ (25,708,000)
Adjustments to reconcile net income to operating cash flows:
Depreciation and amortization	205,706,000	68,733,000
Equity-based compensation expense	22,812,000	2,534,000
Non-cash interest expense	17,813,000	1,034,000
Loss on sale or disposal of assets	1,540,000	3,339,000
Loss on early extinguishment of debt	1,650,000	0
Goodwill and intangible impairments	393,446,000	0
Asset impairments	8,444,000	2,469,000
Pension and other postretirement benefit obligations, net of contributions	(77,274,000)	(1,116,000)
Change in other assets and liabilities, net	50,028,000	47,245,000
Net cash provided by operating activities	74,280,000	98,530,000
Cash flows from investing activities:
Acquisitions, net of cash acquired	0	(49,666,000)
Purchase of property, plant and equipment	(28,944,000)	(7,281,000)
Proceeds from sale of real estate and other assets	26,186,000	10,314,000
Insurance proceeds received for damage to property	1,643,000	0
Change in other investing activities	(864,000)	0
Net cash used for investing activities	(1,979,000)	(46,633,000)
Cash flows from financing activities:
Repayments under term loans	(27,619,000)	(11,296,000)
Borrowings under revolving credit facility	0	136,400,000
Repayments under revolving credit facility	0	(128,400,000)
Deferred payments for acquisitions	7,544,000	0
Payments for employee taxes withheld from stock awards	(1,960,000)	(716,000)
Issuance of common stock	4,000	0
Payment of dividends	0	(68,886,000)
Changes in other financing activities	(352,000)	0
Net cash used for financing activities	(37,471,000)	(72,898,000)
Effect of currency exchange rate change on cash	439,000	0
Increase (decrease) in cash, cash equivalents and restricted cash	35,269,000	(21,001,000)
Balance of cash, cash equivalents and restricted cash at beginning of period	188,664,000	52,770,000
Balance of cash, cash equivalents and restricted cash at end of period	223,933,000	31,769,000
Supplemental cash flow information:
Cash paid for taxes, net of refunds	(4,510,000)	1,046,000
Cash paid for interest	176,402,000	22,902,000
Non-cash investing and financing activities:
Accrued capital expenditures	$ 758,000	$ 105,000