For a classified balance sheet, the carrying amount as of the balance sheet date of the portion of the obligations recognized for the various post employment and postretirement benefits provided to former or inactive employees, their beneficiaries, and covered dependents that is payable after one year (or beyond the operating cycle if longer. Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet due to materiality considerations. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer).

No definition available.

Revision to Previously Reported Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Prepaid expenses and other	$ 110,635	$ 106,478
Assets, Current	2,904,333	2,506,747
Property, plant and equipment, net	556,873	563,564
Other Assets, Noncurrent	221,426	253,054
Identifiable assets	5,314,677	4,938,277	$ 4,649,369
Contract liabilities	194,227	221,095
Liabilities, Current	1,141,633	1,117,442
Retirement obligations and other liabilities	516,087	530,994
Retained Earnings (Accumulated Deficit)	3,656,449	3,652,244
Stockholders' Equity Attributable to Parent	1,732,470	1,746,739
Stockholders' equity	1,762,800	1,772,341	1,632,003	$ 1,658,531
Liabilities and Equity	5,314,677	4,938,277
Net Cash Provided by (Used in) Operating Activities	310,537	324,097	190,831
Net Cash Provided by (Used in) Investing Activities	(41,700)	(33,383)	(81,466)
Net Cash Provided by (Used in) Financing Activities	147,587	(231,464)	(173,284)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 1,095,274	670,980	$ 619,683	703,445
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Prepaid expenses and other		105,101
Assets, Current		2,505,370
Property, plant and equipment, net		572,175
Other Assets, Noncurrent		227,185
Identifiable assets		4,919,642
Contract liabilities		216,541
Liabilities, Current		1,112,888
Retirement obligations and other liabilities		473,295
Retained Earnings (Accumulated Deficit)		3,695,862
Stockholders' Equity Attributable to Parent		1,790,357
Stockholders' equity		1,815,959
Liabilities and Equity		4,919,642
Net Cash Provided by (Used in) Operating Activities		312,741
Net Cash Provided by (Used in) Investing Activities		(23,837)
Net Cash Provided by (Used in) Financing Activities		(229,654)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		670,980
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Prepaid expenses and other		1,377
Assets, Current		1,377
Property, plant and equipment, net		(8,611)
Other Assets, Noncurrent		25,869
Identifiable assets		18,635
Contract liabilities		4,554
Liabilities, Current		4,554
Retirement obligations and other liabilities		57,699
Retained Earnings (Accumulated Deficit)		(43,618)		$ 28,800
Stockholders' Equity Attributable to Parent		(43,618)
Stockholders' equity		(43,618)
Liabilities and Equity		18,635
Net Cash Provided by (Used in) Operating Activities		11,356
Net Cash Provided by (Used in) Investing Activities		(9,546)
Net Cash Provided by (Used in) Financing Activities		(1,810)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		$ 0