Triumph (TGI) 10-Q 3 Feb 21 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Dec. 31, 2020	Feb. 01, 2021
Document Information [Line Items]
Document Period End Date	Dec. 31, 2020
Entity Registrant Name	TRIUMPH GROUP, INC.
Entity Central Index Key	0001021162
Document Type	10-Q
Amendment Flag	false
Current Fiscal Year End Date	--03-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		54,978,278
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	51-0347963
Entity File Number	1-12235
Entity Address, Address Line One	899 Cassatt Road
Entity Address, Address Line Two	Suite 210
Entity Address, City or Town	Berwyn
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19312
City Area Code	610
Local Phone Number	251-1000
Document Quarterly Report	true
Document Transition Report	false
Common Stock [Member]
Document Information [Line Items]
Title of 12(b) Security	Common Stock, par value $.001 per share
Trading Symbol	TGI
Security Exchange Name	NYSE
Purchase Rights [Member]
Document Information [Line Items]
Title of 12(b) Security	Purchase Rights
No Trading Symbol Flag	true
Security Exchange Name	NYSE

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020	[1]
Current assets:
Cash and cash equivalents	$ 477,276	$ 485,463
Trade and other receivables, less allowance for credit losses of $7,743 and $4,293	167,694	359,487
Contract assets	158,289	244,417
Inventory, net	446,208	452,976
Assets held for sale	71,177
Prepaid expenses and other current assets	17,857	19,289
Total current assets	1,338,501	1,561,632
Property and equipment, net	356,107	418,141
Goodwill	521,416	513,527
Intangible assets, net	113,040	381,968
Other, net	72,858	105,065
Total assets	2,401,922	2,980,333
Current liabilities:
Current portion of long-term debt	6,090	7,336
Accounts payable	195,300	457,694
Contract liabilities	167,772	295,320
Accrued expenses	224,367	227,403
Liabilities related to assets held for sale	45,826
Total current liabilities	639,355	987,753
Long-term debt, less current portion	2,013,255	1,800,171
Accrued pension and other postretirement benefits	570,609	660,065
Deferred income taxes	8,028	7,439
Other noncurrent liabilities	240,505	306,169
Stockholders' deficit:
Common stock, $.001 par value, 100,000,000 shares authorized, 55,309,922 and 52,460,920 shares issued; 54,975,059 and 51,858,089 shares outstanding	55	52
Capital in excess of par value	835,193	804,830
Treasury stock, at cost, 334,863 and 602,831 shares	(18,037)	(36,217)
Accumulated other comprehensive loss	(706,169)	(746,448)
Accumulated deficit	(1,180,872)	(803,481)
Total stockholders' deficit	(1,069,830)	(781,264)
Total liabilities and stockholders' deficit	$ 2,401,922	$ 2,980,333
[1]	As adjusted; refer to Note 1.

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020	[1]
Statement Of Financial Position [Abstract]
Allowance for credit losses	$ 7,743	$ 4,293
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	55,309,922	52,460,920
Common stock, shares outstanding	54,975,059	51,858,089
Treasury stock, shares	334,863	602,831
[1]	As adjusted; refer to Note 1.

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		3 Months Ended			9 Months Ended
		Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net sales		$ 425,994	$ 704,666	[1]	$ 1,402,886	$ 2,207,007	[1]
Operating costs and expenses:
Cost of sales (exclusive of depreciation shown separately below)		340,753	546,282	[1]	1,116,668	1,750,751	[1]
Selling, general and administrative		48,747	65,974	[1]	162,189	194,512	[1]
Depreciation and amortization		22,119	29,843	[1]	72,819	104,112	[1]
Impairment of long-lived assets					252,382
Restructuring		4,071	4,744	[1]	32,747	13,490	[1]
Legal judgment gain, net of expenses	[1]		(3,857)			(9,257)
Loss on sale of assets and businesses		(45,273)	(60,019)	[1]	(46,020)	(55,190)	[1]
Operating Expenses		460,963	703,005	[1]	1,682,825	2,108,798	[1]
Operating (loss) income		(34,969)	1,661	[1]	(279,939)	98,209	[1]
Non-service defined benefit income		(12,432)	(14,799)	[1]	(37,275)	(56,025)	[1]
Interest expense and other, net		44,881	33,178	[1]	132,344	96,069	[1]
(Loss) income from continuing operations before income taxes		(67,418)	(16,718)	[1]	(375,008)	58,165	[1]
Income tax expense (benefit)		698	(3,512)	[1]	2,383	12,213	[1]
Net (loss) income		$ (68,116)	$ (13,206)	[1]	$ (377,391)	$ 45,952	[1]
(Loss) earnings per share—basic:
Net (loss) income		$ (1.30)	$ (0.26)	[1]	$ (7.24)	$ 0.92	[1]
Weighted average common shares outstanding—basic		52,488	50,395	[1]	52,126	50,074	[1]
(Loss) earnings per share—diluted:
Net (loss) income		$ (1.30)	$ (0.26)	[1]	$ (7.24)	$ 0.91	[1]
Weighted average common shares outstanding—diluted		52,488	50,395	[1]	52,126	50,591	[1]
Dividends declared and paid per common share	[1]		$ 0.04			$ 0.12
[1]	As adjusted; refer to Note 1.

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive (Loss) Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	[1]	Dec. 31, 2020	Dec. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income		$ (68,116)	$ (13,206)		$ (377,391)	$ 45,952	[1]
Other comprehensive income (loss):
Foreign currency translation adjustment		12,637	11,074		20,838	2,164	[1]
Amounts arising during the period - net of tax expense
Prior service cost, net of taxes of $0 and $0, respectively	[1]					(4,898)
Actuarial loss, net of taxes of $0 and $0, respectively	[1]					(118,073)
Reclassification to net (loss) income - net of expense
Amortization of net loss, net of taxes of $0 and $0, respectively		5,298	5,846		15,894	15,035	[1]
Recognized prior service (credits) cost, net of taxes of $0 and $0, respectively		(1,033)	(1,459)		(3,099)	46,044	[1]
Total defined benefit pension plans and other postretirement benefits (expense), net of taxes		4,265	4,387		12,795	(61,892)	[1]
Cash flow hedges:
Unrealized gain arising during the period, net of tax expense of $0 and $0 respectively		1,878	4,581		8,308	4,921	[1]
Reclassification of gain (loss) included in net earnings, net of tax expense of $0 and $0 respectively		437	(80)		(1,662)	(1,817)	[1]
Net unrealized gain on cash flow hedges, net of tax		2,315	4,501		6,646	3,104	[1]
Total other comprehensive income (loss)		19,217	19,962		40,279	(56,624)	[1]
Total comprehensive (loss) income		$ (48,899)	$ 6,756		$ (337,112)	$ (10,672)	[1]
[1]	As adjusted; refer to Note 1.

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive (Loss) Income (Parenthetical) (Unaudited) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	[1]	Dec. 31, 2020	Dec. 31, 2019	[1]
Statement Of Income And Comprehensive Income [Abstract]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Tax	$ 0	$ 0		$ 0	$ 0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During the Period, Tax	0	0		0	0
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net (Gain) Loss, Tax	0	0		0	0
Other Comprehensive Income (Loss), Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service (Cost) Credit, Tax	0	0		0	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	0	0		0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	$ 0	$ 0		$ 0	$ 0
[1]	As adjusted; refer to Note 1.

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Deficit - USD ($) $ in Thousands		Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock [Member]	Capital in Excess of Par Value [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member]Cumulative Effect, Period of Adoption, Adjustment
Balance at Mar. 31, 2019	[1]	$ (573,313)	$ (225)	$ 52	$ 867,545	$ (159,154)	$ (516,011)	$ (765,745)	$ (225)
Balance (in shares) at Mar. 31, 2019	[1]			49,887,268
Net income (loss)	[1]	$ 16,924						16,924
Accounting Standards Update [Extensible List]	[1]	us-gaap:AccountingStandardsUpdate201602Member
Foreign currency translation adjustment	[1]	$ (2,683)					(2,683)
Pension liability adjustment, net of income taxes	[1]	2,573					2,573
Change in fair value of foreign currency hedges, net of income taxes	[1]	(319)					(319)
Cash dividends	[1]	(1,998)						(1,998)
Share-based compensation	[1]	1,903			(7,631)	9,534
Share-based compensation, shares	[1]			154,802
Repurchase of shares for share-based compensation minimum tax obligation	[1]	(1,043)				(1,043)
Repurchase of shares for share-based compensation minimum tax obligation, shares	[1]			(51,406)
Employee stock purchase plan	[1]	262			(634)	896
Employee stock purchase plan, shares	[1]			14,489
Balance at Jun. 30, 2019	[1]	(557,919)		$ 52	859,280	(149,767)	(516,440)	(751,044)
Balance (in shares) at Jun. 30, 2019	[1]			50,005,153
Balance at Mar. 31, 2019	[1]	(573,313)	$ (225)	$ 52	867,545	(159,154)	(516,011)	(765,745)	$ (225)
Balance (in shares) at Mar. 31, 2019	[1]			49,887,268
Foreign currency translation adjustment	[1]	2,164
Balance at Dec. 31, 2019	[1]	(532,897)		$ 52	804,133	(38,424)	(572,635)	(726,023)
Balance (in shares) at Dec. 31, 2019	[1]			51,829,774
Balance at Jun. 30, 2019	[1]	(557,919)		$ 52	859,280	(149,767)	(516,440)	(751,044)
Balance (in shares) at Jun. 30, 2019	[1]			50,005,153
Net income (loss)	[1]	42,234						42,234
Foreign currency translation adjustment	[1]	(6,227)					(6,227)
Pension liability adjustment, net of income taxes	[1]	(68,852)					(68,852)
Change in fair value of foreign currency hedges, net of income taxes	[1]	(1,078)					(1,078)
Cash dividends	[1]	(2,003)						(2,003)
Share-based compensation	[1]	2,804			(850)	3,654
Share-based compensation, shares	[1]			59,938
Repurchase of shares for share-based compensation minimum tax obligation	[1]	(5)				(5)
Repurchase of shares for share-based compensation minimum tax obligation, shares	[1]			(764)
Employee stock purchase plan	[1]	222			(400)	622
Employee stock purchase plan, shares	[1]			10,196
Balance at Sep. 30, 2019	[1]	(590,824)		$ 52	858,030	(145,496)	(592,597)	(710,813)
Balance (in shares) at Sep. 30, 2019	[1]			50,074,523
Net income (loss)	[1]	(13,206)						(13,206)
Foreign currency translation adjustment	[1]	11,074					11,074
Pension liability adjustment, net of income taxes	[1]	4,387					4,387
Change in fair value of foreign currency hedges, net of income taxes	[1]	4,501					4,501
Cash dividends	[1]	(2,004)						(2,004)
Share-based compensation	[1]	3,068			1,927	1,141
Share-based compensation, shares	[1]			18,723
Repurchase of shares for share-based compensation minimum tax obligation	[1]	(131)				(131)
Repurchase of shares for share-based compensation minimum tax obligation, shares	[1]			(5,092)
Employee stock purchase plan	[1]	238			(428)	666
Employee stock purchase plan, shares	[1]			10,917
Contribution of treasury shares to pension plan, shares	[1]	50,000			(55,396)	105,396
Contribution of treasury shares to pension plan	[1]			1,730,703
Balance at Dec. 31, 2019	[1]	(532,897)		$ 52	804,133	(38,424)	(572,635)	(726,023)
Balance (in shares) at Dec. 31, 2019	[1]			51,829,774
Balance at Mar. 31, 2020	[1]	(781,264)		$ 52	804,830	(36,217)	(746,448)	(803,481)
Balance (in shares) at Mar. 31, 2020	[1]			51,858,089
Net income (loss)	[1]	(275,786)						(275,786)
Foreign currency translation adjustment	[1]	919					919
Pension liability adjustment, net of income taxes	[1]	4,265					4,265
Change in fair value of foreign currency hedges, net of income taxes	[1]	2,100					2,100
Share-based compensation	[1]	2,621			(6,670)	9,291
Share-based compensation, shares	[1]			158,274
Repurchase of shares for share-based compensation minimum tax obligation	[1]	(474)				(474)
Repurchase of shares for share-based compensation minimum tax obligation, shares	[1]			(50,955)
Employee stock purchase plan	[1]	238			(1,974)	2,212
Employee stock purchase plan, shares	[1]			36,802
Balance at Jun. 30, 2020	[1]	(1,047,381)		$ 52	796,186	(25,188)	(739,164)	(1,079,267)
Balance (in shares) at Jun. 30, 2020	[1]			52,002,210
Balance at Mar. 31, 2020	[1]	(781,264)		$ 52	804,830	(36,217)	(746,448)	(803,481)
Balance (in shares) at Mar. 31, 2020	[1]			51,858,089
Foreign currency translation adjustment		20,838
Balance at Dec. 31, 2020		(1,069,830)		$ 55	835,193	(18,037)	(706,169)	(1,180,872)
Balance (in shares) at Dec. 31, 2020				54,975,059
Balance at Jun. 30, 2020	[1]	(1,047,381)		$ 52	796,186	(25,188)	(739,164)	(1,079,267)
Balance (in shares) at Jun. 30, 2020	[1]			52,002,210
Net income (loss)	[1]	(33,489)						(33,489)
Foreign currency translation adjustment	[1]	7,282					7,282
Pension liability adjustment, net of income taxes	[1]	4,265					4,265
Change in fair value of foreign currency hedges, net of income taxes	[1]	2,231					2,231
Share-based compensation	[1]	2,536			(446)	2,982
Share-based compensation, shares	[1]			54,313
Repurchase of shares for share-based compensation minimum tax obligation	[1]	(21)				(21)
Repurchase of shares for share-based compensation minimum tax obligation, shares	[1]			(2,246)
Employee stock purchase plan	[1]	219			(1,122)	1,341
Employee stock purchase plan, shares	[1]			24,413
Balance at Sep. 30, 2020	[1]	(1,064,357)		$ 52	794,619	(20,886)	(725,386)	(1,112,756)
Balance (in shares) at Sep. 30, 2020	[1]			52,078,690
Net income (loss)		(68,116)						(68,116)
Foreign currency translation adjustment		12,637					12,637
Pension liability adjustment, net of income taxes		4,265					4,265
Change in fair value of foreign currency hedges, net of income taxes		2,315					2,315
Share-based compensation		3,615			2,457	1,158
Share-based compensation, shares				31,967
Repurchase of shares for share-based compensation minimum tax obligation		(57)				(57)
Repurchase of shares for share-based compensation minimum tax obligation, shares				(5,876)
Employee stock purchase plan		203			(1,545)	1,748
Employee stock purchase plan, shares				21,276
Contribution of common stock to pension plan		39,665		$ 3	39,662
Contribution of common stock to pension plan, shares				2,849,002
Balance at Dec. 31, 2020		$ (1,069,830)		$ 55	$ 835,193	$ (18,037)	$ (706,169)	$ (1,180,872)
Balance (in shares) at Dec. 31, 2020				54,975,059
[1]	As adjusted; refer to Note 1.

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Stockholders' Deficit (Parenthetical) - USD ($) $ in Thousands

3 Months Ended

Dec. 31, 2020

Sep. 30, 2020

[1]

Jun. 30, 2020

[1]

Dec. 31, 2019

Sep. 30, 2019

Jun. 30, 2019

Statement Of Stockholders Equity Parenthetical [Abstract]

Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, tax

$ 0

$ 0

$ 0

$ 0

[1]

$ 0

[1]

$ 0

[1]

Other comprehensive income (loss), tax

$ 0

$ 0

$ 0

$ 0

[1]

$ 0

[1]

$ 0

[1]

Dividends declared and paid per common share (in dollars per share)

[1]

$ 0.04

$ 0.04

$ 0.04

[1]

As adjusted; refer to Note 1.

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating Activities
Net (loss) income	$ (377,391)	$ 45,952	[1]
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	72,819	104,112	[1]
Impairment of long-lived assets	252,382
Amortization of acquired contract liability	(35,017)	(56,153)
Loss on sale of assets and businesses	46,020	55,190	[1]
Curtailments and special termination benefits gain, net		(14,373)
Other amortization included in interest expense	21,912	9,114
Provision for credit losses	4,890	632
Provision for deferred income taxes		8,108
Share-based compensation	9,086	8,245
Changes in other assets and liabilities, excluding the effects of acquisitions and divestitures:
Trade and other receivables	169,744	72,278
Contract assets	55,170	53,047
Inventories	(2,152)	(67,764)
Prepaid expenses and other current assets	1,041	11,315
Accounts payable, accrued expenses, and contract liabilities	(375,967)	(143,718)
Accrued pension and other postretirement benefits	(36,838)	(45,702)
Other, net	(1,570)	(995)
Net cash (used in) provided by operating activities	(195,871)	39,288
Investing Activities
Capital expenditures	(18,988)	(27,250)
Proceeds from sale of assets and businesses	2,380	49,956
Net cash (used in) provided by investing activities	(16,608)	22,706
Financing Activities
Net decrease in revolving credit facility	(400,000)	(215,000)
Proceeds from issuance of long-term debt	713,900	570,980
Retirement of debt and finance lease obligations	(95,439)	(433,197)
Payment of deferred financing costs	(20,215)	(17,545)
Dividends paid		(6,005)
Repurchase of restricted shares for minimum tax obligations	(552)	(1,179)
Net cash provided by (used in) financing activities	197,694	(101,946)
Effect of exchange rate changes on cash	6,598	739
Net change in cash and cash equivalents	(8,187)	(39,213)
Cash and cash equivalents at beginning of period	485,463	92,807
Cash and cash equivalents at end of period	$ 477,276	$ 53,594
[1]	As adjusted; refer to Note 1.

Background and Basis of Present

Background and Basis of Presentation	9 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Background and Basis of Presentation	1. BACKGROUND AND BASIS OF PRESENTATION The accompanying unaudited condensed consolidated financial statements of Triumph Group, Inc. ("Triumph") have been prepared in conformity with accounting principles generally accepted in the United States ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, the interim financial information includes all adjustments of a normal recurring nature necessary for a fair presentation of the results of operations, financial position and cash flows. The results of operations for the three and nine months ended December 31, 2020 and 2019, are not necessarily indicative of results that may be expected for the year ending March 31, 2021. The accompanying condensed consolidated financial statements are unaudited and should be read in conjunction with the fiscal 2020 audited consolidated financial statements and notes thereto included in the Company's Form 10-K for the fiscal year ended March 31, 2020, filed with the Securities and Exchange Commission (the "SEC") on May 28, 2020. Triumph is a Delaware corporation which, through its operating subsidiaries, designs, engineers, manufactures, and sells products for the global aerospace original equipment manufacturers ("OEMs") of aircraft and aircraft components and repairs and overhauls aircraft components and accessories for commercial airline, air cargo carrier and military customers on a worldwide basis. Triumph and its subsidiaries (collectively, the "Company") are organized based on the products and services that they provide. The Company has two reportable segments: Systems & Support and Aerospace Structures. Systems & Support consists of the Company’s operations that provide integrated solutions, including design; development; and support of proprietary components, subsystems and systems, as well as production of complex assemblies using external designs. Capabilities include hydraulic, mechanical and electromechanical actuation, power and control; a complete suite of aerospace gearbox solutions, including engine accessory gearboxes and helicopter transmissions; active and passive heat exchange technology; fuel pumps, fuel metering units and Full Authority Digital Electronic Control fuel systems; hydromechanical and electromechanical primary and secondary flight controls. Systems & Support also provides full life cycle solutions for commercial, regional and military aircraft. The Company’s extensive product and service offerings include full post-delivery value chain services that simplify the maintenance, repair, and overhaul (“MRO”) supply chain. Through its ground support equipment maintenance, component MRO and post-production supply chain activities, Systems & Support is positioned to provide integrated planeside repair solutions globally. Capabilities include metallic and composite aircraft structures; nacelles; thrust reversers; interiors; auxiliary power units; and a wide variety of pneumatic, hydraulic, fuel and mechanical accessories. Repair services generally involve the replacement and/or remanufacturing of parts, which is similar to the original manufacture of the part. The processes that the Company performs related to repair and overhaul services are essentially the repair of wear parts or replacement of parts that are beyond economic repair. The repair service generally involves remanufacturing a complete part or a component of a part. Aerospace Structures consists of the Company’s operations that supply commercial, business, regional and military manufacturers with large metallic and composite structures and aircraft interior systems, including air ducting and thermal acoustic insulations systems. Products include wings; wing boxes; fuselage panels; horizontal and vertical tails; subassemblies such as floor grids; and aircraft interior systems, including air ducting and thermal acoustic insulations systems. Aerospace Structures also has the capability to engineer detailed structural designs in metal and composites. Capabilities include advanced composite and interior structures, joining processes such as welding, autoclave bonding, and conventional mechanical fasteners. The accompanying condensed consolidated financial statements include the accounts of Triumph and its wholly-owned subsidiaries. Intercompany accounts and transactions have been eliminated from the accompanying condensed consolidated financial statements. Standards Recently Implemented Adoption of ASU 2016-13 In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. The Company adopted ASU 2018-13 effective April 1, 2020 , and the adoption did not have a significant impact on its consolidated financial statement disclosures. Standards Issued Not Yet Implemented In August 2018, the FASB issued ASU 2018-14, Compensation—Retirement Benefits—Defined Benefit Plans—General (Subtopic 715-20): Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans Impact of Change in Accounting Principle Effective April 1, 2020, the Company changed its method of accounting for the determination of the market-related value of assets (“MRVA”) for a class of assets (fixed income securities) within the qualified U.S. defined benefit plan (the “Plan”) which is used in determining the expected return on asset component of net periodic benefit income. This class of assets is comprised solely of the fixed income securities asset class held in the portfolio for the Plan, which provides a natural hedge (liability-hedging assets) against the changes in the recorded amount of net periodic pension cost. Refer to Note 15 in the Company’s Form 10-K for the fiscal year ended March 31, 2020, for its fair value disclosure by asset classification. The Company’s previous method of accounting was to calculate the MRVA for all the Plan’s assets recognizing investment gains and losses into the MRVA over a five-year period. T he Company has changed its method of accounting and elected to use the fair value of our fixed income assets, which represent approximately 44% of the Plan’s assets, to determine the MRVA beginning in the second quarter of fiscal 2021. This change in accounting principle is preferable as it results in an expected return on asset component of net periodic benefit income that more accurately reflects the changes in the fair values of the fixed income securities. No change is being made to the accounting principle for the other classes of pension assets, which represent the remaining 56% of the pension asset five-year The change in accounting principle requires retrospective application and prospective disclosure. The Company applied the change effective April 1, 2020, and recorded a cumulative adjustment to equity as of the earliest period presented. The tables below represent the impact of this change on the condensed consolidated statements of operations (including earnings per share) and the condensed consolidated statements of comprehensive (loss) income for the periods presented below. The change in accounting principle had no impact on the condensed consolidated statements of cash flows for these periods. The tables below represent the impact of the change in accounting principle on the condensed consolidated statement of operations and the condensed consolidated statements of comprehensive loss for the three and nine months ended December 31, 2020. Three Months Ended Nine Months Ended As Reported (With Change), December 31, 2020 Impact of Change Without Change, December 31, 2020 As Reported (With Change), December 31, 2020 Impact of Change Without Change, December 31, 2020 Non-service defined benefit income $ (12,432 ) $ (1,528 ) $ (13,960 ) $ (37,275 ) $ (4,584 ) $ (41,859 ) Loss before income taxes (67,418 ) 1,528 (65,890 ) (375,008 ) 4,584 (370,424 ) Income tax expense 698 - 698 2,383 - 2,383 Net loss $ (68,116 ) $ 1,528 $ (66,588 ) $ (377,391 ) $ 4,584 $ (372,807 ) Net Loss per share - basic & diluted Basic $ (1.30 ) $ 0.03 $ (1.27 ) $ (7.24 ) $ 0.09 $ (7.15 ) Diluted $ (1.30 ) $ 0.03 $ (1.27 ) $ (7.24 ) $ 0.09 $ (7.15 ) Defined benefit pension plans and other postretirement benefits: Total defined benefit pension plans and other postretirement benefits, net of taxes $ 4,265 $ (1,528 ) $ 2,737 $ 12,795 $ (4,584 ) $ 8,211 Total other comprehensive income $ 19,217 $ (1,528 ) $ 17,689 $ 40,279 $ (4,584 ) $ 35,695 Comprehensive loss $ (48,899 ) $ - $ (48,899 ) $ (337,112 ) $ - $ (337,112 ) The table below represents the impact of the change in accounting principle on the condensed consolidated balance sheet as of December 31, 2020. Stockholders' deficit: As Reported (With Change), December 31, 2020 Impact of Change Without Change, December 31, 2020 Accumulated other comprehensive loss $ (706,169 ) $ (31,604 ) $ (737,773 ) Accumulated deficit $ (1,180,872 ) $ 31,604 $ (1,149,268 ) Total stockholders' deficit $ (1,069,830 ) $ - $ (1,069,830 ) The tables below represent the impact of the change in accounting principle on the condensed consolidated statement of operations and the condensed consolidated statements of comprehensive income (loss) for the three and nine months ended December 31, 2019. Three Months Ended Nine Months Ended As Previously Reported, December 31, 2019 Impact of Change As Reported, December 31, 2019 As Previously Reported, December 31, 2019 Impact of Change As Reported, December 31, 2019 Non-service defined benefit income $ (13,989 ) (810 ) $ (14,799 ) $ (57,280 ) 1,255 $ (56,025 ) (Loss) income before income taxes (17,528 ) 810 (16,718 ) 59,420 (1,255 ) 58,165 Income tax (benefit) expense (3,682 ) 170 (3,512 ) 12,477 (264 ) 12,213 Net (loss) income $ (13,846 ) $ 640 $ (13,206 ) $ 46,943 $ (991 ) $ 45,952 Net (Loss) Income per share - basic & diluted Basic $ (0.27 ) $ 0.01 $ (0.26 ) $ 0.94 $ (0.02 ) $ 0.92 Diluted $ (0.27 ) $ 0.01 $ (0.26 ) $ 0.93 $ (0.02 ) $ 0.91 Defined benefit pension plans and other postretirement benefits (expense): Total defined benefit pension plans and other postretirement benefits (expense), net of taxes $ 5,027 $ (640 ) $ 4,387 $ (62,883 ) $ 991 $ (61,892 ) Total other comprehensive income (loss) $ 20,602 $ (640 ) $ 19,962 $ (57,615 ) $ 991 $ (56,624 ) Comprehensive income (loss) $ 6,756 $ - $ 6,756 $ (10,672 ) $ - $ (10,672 ) The table below represents the impact of the change in accounting principle on the condensed consolidated balance sheet as of March 31, 2020. As Previously Reported, March 31, 2020 Impact of Change As Reported, March 31, 2020 Stockholders' deficit: Accumulated other comprehensive loss $ (719,428 ) $ (27,020 ) $ (746,448 ) Accumulated deficit (830,501 ) 27,020 (803,481 ) Total stockholders' deficit $ (781,264 ) $ - $ (781,264 )

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Use of Estimates The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Revenue Recognition and Contract Balances The Company's revenue is principally from contracts with customers to provide design, development, manufacturing, and support services associated with specific customer programs. The Company regularly enters into long-term master supply agreements that establish general terms and conditions and may define specific program requirements. Many agreements include clauses that provide sole supplier status to the Company for the duration of the program’s life. Purchase orders (or authorizations to proceed) are issued pursuant to the master supply agreements. Additionally, a majority of the Company’s agreements with customers include options for future purchases. Such options primarily reduce the administrative effort of issuing subsequent purchase orders and do not represent material rights granted to customers. The Company generally enters into agreements directly with its customers and is the principal in all current contracts. The identification of a contract with a customer for purposes of accounting and financial reporting requires an evaluation of the terms and conditions of agreements to determine whether presently enforceable rights and obligations exist. Management considers a number of factors when making this evaluation that include, but are not limited to, the nature and substance of the business exchange, the specific contractual terms and conditions, the promised products and services, the termination provisions in the contract, as well as the nature and execution of the customer’s ordering process and how the Company is authorized to perform work. Generally, presently enforceable rights and obligations are not created until a purchase order is issued by a customer for a specified number of units of product or services. Therefore, the issuance of a purchase order is generally the point at which a contract is identified for accounting and financial reporting purposes. Management identifies the promises to the customer. Promises are generally explicitly stated in each contract, but management also evaluates whether any promises are implied based on the terms of the agreement, past business practice, or other facts and circumstances. Each promise is evaluated to determine if it is a performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service. The Company considers a number of factors when determining whether a promise is a distinct performance obligation, including whether the customer can benefit from the good or service on its own or together with other resources that are readily available to the customer, whether the Company provides a significant service of integrating goods or services to deliver a combined output to the customer, or whether the goods or services are highly interdependent. The Company’s performance obligations consist of a wide range of engineering design services and manufactured components, as well as spare parts and repairs for OEMs. The transaction price for a contract reflects the consideration the Company expects to receive for fully satisfying the performance obligations in the contract. Typically, the transaction price consists solely of fixed consideration but may include variable consideration for contractual provisions such as unpriced contract modifications, cost-sharing provisions, and other receipts or payments to customers. The Company identifies and estimates variable consideration, typically at the most likely amount the Company expects to receive from its customers. Variable consideration is only included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized for the contract will not occur, or when the uncertainty associated with the variable consideration is resolved. The Company's contracts with customers generally require payment under normal commercial terms after delivery with payment typically required within 30 to 120 days of delivery. However, a subset of the Company’s current contracts includes significant financing components because the timing of the transfer of the underlying products and services under contract are at the customers’ discretion. For these contracts, the Company adjusts the transaction price to reflect the effects of the time value of money. The Company generally is not subject to collecting sales tax and has made an accounting policy election to exclude from the transaction price any sales and other similar taxes collected from customers. As a result, any such collections are accounted for on a net basis. The total transaction price is allocated to each of the identified performance obligations using the relative stand-alone selling price. The objective of the allocation is to reflect the consideration that the Company expects to receive in exchange for the products or services associated with each performance obligation. Stand-alone selling price is the price at which the Company would sell a promised good or service separately to a customer. Stand-alone selling prices are established at contract inception, and subsequent changes in transaction price are allocated on the same basis as at contract inception. When stand-alone selling prices for the Company’s products and services are not observable, the Company uses either the “Expected Cost Plus a Margin” or "Adjusted Market Assessment" approaches to estimate stand-alone selling price. Expected costs are typically derived from the available periodic forecast information. Revenue is recognized when or as control of promised products or services transfers to a customer and is recognized at the amount allocated to each performance obligation associated with the transferred products or services. Service sales, principally representing repair, maintenance, and engineering activities are recognized over the contractual period or as services are rendered. Sales under long-term contracts with performance obligations satisfied over time are recognized using either an input or output method. The Company recognizes revenue over time as it performs on these contracts because of the continuous transfer of control to the customer as represented by contractual terms that entitle the Company to the reimbursement of costs plus a reasonable profit for work performed to manufacture products for which the Company has no alternate use or for work performed on a customer-owned asset. With control transferring over time, revenue is recognized based on the extent of progress toward completion of the performance obligation. The Company generally uses the cost-to-cost input method of progress for its contracts because it best depicts the transfer of control to the customer that occurs as work progresses. Under the cost-to-cost method, the extent of progress toward completion is measured based on the proportion of costs incurred to date to the total estimated costs at completion of the performance obligation. The Company reviews its cost estimates on contracts on a periodic basis, or when circumstances change and warrant a modification to a previous estimate. Cost estimates are largely based on negotiated or estimated purchase contract terms, historical performance trends and other economic projections. Significant factors that influence these estimates include inflationary trends, technical and schedule risk, internal and subcontractor performance trends, business volume assumptions, asset utilization, and anticipated labor agreements. Revenue and cost estimates are regularly monitored and revised based on changes in circumstances. Impacts from changes in estimates of net sales and cost of sales are recognized on a cumulative catch-up basis, which recognizes in the current period the cumulative effect of the changes on current and prior periods based on a performance obligation’s percentage of completion. Forward loss reserves for anticipated losses on long-term contracts are recorded in full when such losses become evident, to the extent required, and are included in contract liabilities on the accompanying condensed consolidated balance sheets. The Company believes that the accounting estimates and assumptions made by management are appropriate given the increased uncertainties surrounding the severity and duration of the impacts of the COVID-19 pandemic; however, actual results could differ materially from those estimates. For the three months ended December 31, 2020, cumulative catch-up adjustments resulting from changes in contract values and estimated costs that arose during the fiscal year decreased revenue, operating loss, net loss and loss per share by approximately ($37), $3,688, $3,688, and $0.07, respectively. For the three months ended December 31, 2019, cumulative catch-up adjustments resulting from changes in estimates increased net sales by approximately $4,722 and decreased operating income, net income, and earnings per share by approximately ($210), ($166), and $0.00, respectively. For the nine months ended December 31, 2020, cumulative catch-up adjustments resulting from changes in contract values and estimated costs that arose during the fiscal year increased revenue and decreased operating loss, net loss and loss per share by approximately $4,577, $19,349, $19,349, and $0.37, respectively. For the nine months ended December 31, 2019, cumulative catch-up adjustments resulting from changes in estimates increased net sales by approximately $2,347 and decreased operating income, net income, and earnings per share by approximately ($16,393), ($12,950), and ($0.26), respectively. Revenues for performance obligations that are not recognized over time are recognized at the point in time when control transfers to the customer. For performance obligations that are satisfied at a point in time, the Company evaluates the point in time when the customer can direct the use of and obtain the benefits from the products and services. Generally, the shipping terms determine the point in time when control transfers to customers. Shipping and handling activities are not considered performance obligations and related costs are included in cost of sales as incurred. Differences in the timing of revenue recognition and contractual billing and payment terms result in the recognition contract assets and liabilities. Refer to Note 4 for further discussion. In connection with several prior acquisitions, the Company assumed existing long-term contracts. Based on review of these contracts at the acquisition date, the Company concluded that the terms of certain contracts were either more or less favorable than could be realized in market transactions as of the date of the acquisition. As a result, the Company recognized acquired contract liabilities, net of acquired contract assets as of the acquisition date of each respective acquisition, based on the present value of the difference between the contractual cash flows of the executory contracts and the estimated cash flows had the contracts been executed at the acquisition date. The liabilities principally relate to long-term contracts that were initially executed several years prior to the respective acquisition. The Company measured these net liabilities in the year they were acquired under the measurement provisions of Accounting Standards Codification (“ASC”) 820, Fair Value Measurement Trade and Other Receivables, net Trade and other receivables are recorded net of an allowance for expected credit losses. Trade and other receivables include amounts billed and currently due from customers and amounts retained by the customer pending contract completion. The Company performs ongoing credit evaluations of its customers and generally does not require collateral. The Company pools receivables that share underlying risk characteristics and records the allowance for expected credit losses based on a combination of prior experience, current economic conditions and management’s expectations of future economic conditions, and specific collectibility matters when they arise. The Company writes off balances against the allowance for expected credit losses when collectibility is deemed remote. The Company's trade and other receivables are exposed to credit risk; however, the risk is limited due to the diversity of the customer base. For the three and nine months ended December 31, 2020 and 2019, credit loss expense and write-offs were immaterial. Leases The Company leases office space, manufacturing facilities, land, vehicles, and equipment. The Company determines if an agreement is or contains a lease at the lease inception date and recognizes right-of-use (“ROU”) assets and lease liabilities at the lease commencement date. A ROU asset and corresponding lease liability are not recorded for leases with an initial term of 12 months or less (“short-term leases”). ROU assets represent the Company's right to use an underlying asset during the lease term, and lease liabilities represent the Company's obligation to make lease payments arising from the lease. The determination of the length of lease terms is affected by options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. The existence of significant economic incentive is the primary consideration when assessing whether the Company is reasonably certain of exercising an option in a lease. Both finance and operating lease ROU assets and liabilities are recognized at commencement date and measured as the present value of lease payments to be made over the lease term. As the interest rate implicit in the lease is not readily available for most of the Company's leases, the Company uses its estimated incremental borrowing rate in determining the present value of lease payments. The estimated incremental borrowing rate is derived from information available at the lease commencement date. The lease ROU asset recognized at commencement is adjusted for any lease payments related to initial direct costs, prepayments, and lease incentives. For operating leases, lease expense is recognized on a straight-line basis over the lease term. For finance leases, lease expense comprises the amortization of the ROU assets recognized on a straight-line basis generally over the shorter of the lease term or the estimated useful life of the underlying asset and interest on the lease liability. Variable lease payments not dependent on a rate or index are recognized when the event, activity, or circumstance in the lease agreement upon which those payments are contingent is probable of occurring and are presented in the same line of the consolidated balance sheet as the rent expense arising from fixed payments. The Company has lease agreements with lease and non-lease components. Non-lease components are combined with the related lease components and accounted for as lease components for all classes of underlying assets. Concentration of Credit Risk The Company’s trade and other accounts receivable are exposed to credit risk. However, the risk is limited due to the diversity of the customer base and the customer base’s wide geographical area. Trade accounts receivable from The Boeing Company ("Boeing") (representing commercial, military and space) represented approximately 19% and 21% of total trade accounts receivable as of December 31, 2020 and March 31, 2020, respectively. Trade and other accounts receivable from Bombardier Inc. ("Bombardier") include receivables from transition services and represented approximately 2% and 16% as of December 31, 2020 and March 31, 2020, respectively. The Company had no other concentrations of credit risk of more than 10%. Sales to Boeing for the nine months ended December 31, 2020, were $528,263, or 38% of net sales, of which $164,520 and $363,743 were from Systems & Support and Aerospace Structures, respectively. Sales to Boeing for the nine months ended December 31, 2019, were $742,495, or 34% of net sales, of which $189,854 and $552,641 were from Systems & Support and Aerospace Structures, respectively. The percentage increase in sales to Boeing as compared with the prior period is driven entirely by military sales. Sales to Gulfstream Aerospace Corporation (“Gulfstream”) for the nine months ended December 31, 2020, were $100,364, or 7% of net sales, of which $2,166 and $98,197 were from Systems & Support and Aerospace Structures, respectively. Sales to Gulfstream for the nine months ended December 31, 2019, were $268,917, or 12% of net sales, of which $2,497 and $266,421 were from Systems & Support and Aerospace Structures, respectively. No other single customer accounted for more than 10% of the Company’s net sales. However, the loss of any significant customer, including Boeing and Gulfstream, could have a material adverse effect on the Company and its operating subsidiaries. Fair Value Measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. When determining fair value measurements for assets and liabilities required to be recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and also considers assumptions that market participants would use when pricing an asset or liability. The fair value hierarchy has three levels of inputs that may be used to measure fair value: Level 1—Unadjusted quoted prices in active markets for identical assets or liabilities; Level 2—Unadjusted quoted prices in active markets for similar assets or liabilities, or unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable for the asset or liability; and Level 3—Unobservable inputs for the asset or liability. The Company has applied fair value measurements when measuring the impairment of assets held for sale (see Note 3), when measuring the long-lived asset impairment in the current period (see Note 10), and to its pension and postretirement plan assets (see Note 11). Supplemental Cash Flow Information For the nine months ended December 31, 2020, the Company paid $2,474 for income taxes, net of income tax refunds received. For the nine months ended December 31, 2019, the Company paid $4,370 for income taxes, net of income tax refunds received.

Divested Operations and Assets

Divested Operations and Assets Held For Sale	9 Months Ended
	Dec. 31, 2020
Discontinued Operations And Disposal Groups [Abstract]
Divested Operations and Assets Held For Sale	3. DIVESTED OPERATIONS AND ASSETS HELD FOR SALE Assets Held for Sale In May 2020, the Company’s Board of Directors committed to a plan to sell its composites manufacturing operations located in Milledgeville, Georgia and Rayong, Thailand. In August 2020, the Company entered into a definitive agreement with the buyer of the composites manufacturing operations in Georgia and Thailand. The transaction is expected to close in the fourth quarter of fiscal year 2021. In the three months ended December 31, 2020, the Company recognized an impairment on the assets held for sale of $45,201 due to decreases in actual and expected performance of certain widebody programs within the disposal group that affected its estimated fair value less cost to sell. The impairment is presented on the accompanying consolidated statements of operations within loss on sale of assets and businesses. To measure the amount of the impairment, the Company compared the carrying value of the assets and liabilities of the disposal group with their estimated fair value less cost to sell as of the balance sheet date. The estimate of fair value is categorized as Level 2 within the fair value hierarchy. The key assumptions used in the estimate of fair value is the negotiated sales price of the assets and the assumption of the disposal group’s liabilities. As of December 31, 2020, the operating results of the composites manufacturing operations are included within the Aerospace Structures reportable segment, and the related assets and liabilities are classified as held for sale on the accompanying condensed consolidating balance sheets. Fiscal 2020 Divestitures In August 2020, the Company completed the transfer of the assets and certain liabilities associated with its Gulfstream G650 wing supply chain activities for cash proceeds net of transaction costs of approximately $52,000. The Company recognized a loss of approximately $747, which is presented on the accompanying condensed consolidated statements of operations within loss on sale of assets and businesses. T In December 2019, the Company completed the sale of its manufacturing operations at its Nashville, TN, facility for cash proceeds net of transaction costs of approximately $58,000, including approximately $7,000 allocated as a premium paid by the buyer in exchange for a specified performance guarantee. The Company recognized a loss of approximately $64,000, which is presented on the consolidated statements of operations within loss on sale of assets and businesses. The operating results of the Nashville manufacturing operations are included in Aerospace Structures through the date of divestiture. Additionally, as part of the transaction, the Company agreed to transfer to the buyer, within 120 days from the date of closing, certain defined benefit pension assets and obligations of approximately $55,000 associated with the Nashville manufacturing operations. In accordance with applicable defined benefit pension plan accounting guidance, the transfer was treated as a settlement for purposes of the Company’s consolidated financial statements and resulted in accelerated recognition of previously unrecognized actuarial losses. The Company completed the transfer of the defined benefit pension assets and obligations in March 2020 and recognized a one-time settlement loss of approximately $28,000. In September 2019, the Company completed the assignment of its E-2 Jets contract with Embraer for the manufacture of structural components for their program to AeroSpace Technologies of Korea Inc. ("ASTK"). As part of this transaction, the Company transferred certain assets and liabilities to ASTK and recognized a gain of approximately $10,000, which is presented on the accompanying condensed consolidated statements of operations within loss on sale of assets and businesses. The assets and liabilities transferred were included within Aerospace Structures through the date of divestiture.

Revenue Recognition and Contrac

Revenue Recognition and Contracts with Customers	9 Months Ended
	Dec. 31, 2020
Change In Contract With Customer Asset And Liability [Abstract]
Revenue Recognition and Contracts with Customers	4. REVENUE RECOGNITION AND CONTRACTS WITH CUSTOMERS Disaggregation of Revenue The Company disaggregates revenue based on the method of measuring satisfaction of the performance obligation either over time or at a point in time. Additionally, the Company disaggregates revenue based upon the end market where products and services are transferred to the customer. The Company’s principal operating segments and related revenue are discussed in Note 13, Segments. The following table shows disaggregated net sales satisfied overtime and at a point in time (excluding intercompany sales) for the three and nine months ended December 31, 2020 and 2019: Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 Systems & Support Satisfied over time $ 118,813 $ 135,229 $ 324,968 $ 403,825 Satisfied at a point in time 140,519 193,601 418,753 571,433 Revenue from contracts with customers 259,332 328,830 743,721 975,258 Amortization of acquired contract liabilities 4,306 8,377 11,569 26,126 Total revenue 263,638 337,207 755,290 1,001,384 Aerospace Structures Satisfied over time $ 148,526 $ 330,657 $ 596,145 $ 1,075,141 Satisfied at a point in time 11,269 28,582 28,003 100,455 Revenue from contracts with customers 159,795 359,239 624,148 1,175,596 Amortization of acquired contract liabilities 2,561 8,220 23,448 30,027 Total revenue 162,356 367,459 647,596 1,205,623 $ 425,994 $ 704,666 $ 1,402,886 $ 2,207,007 The following table shows disaggregated net sales by end market (excluding intercompany sales) for the three and nine months ended December 31, 2020 and 2019: Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 Systems & Support Commercial aerospace $ 92,529 $ 192,232 $ 280,102 $ 561,815 Military 145,168 105,860 396,672 309,735 Business jets 7,802 10,776 26,884 45,280 Regional 5,231 11,310 18,218 33,434 Non-aviation 8,602 8,652 21,845 24,994 Revenue from contracts with customers 259,332 328,830 743,721 975,258 Amortization of acquired contract liabilities 4,306 8,377 11,569 26,126 Total revenue $ 263,638 $ 337,207 $ 755,290 $ 1,001,384 Aerospace Structures Commercial aerospace $ 109,929 $ 208,943 $ 372,249 $ 681,471 Military 31,670 27,394 105,365 83,773 Business jets 18,039 98,370 138,141 330,178 Regional — 24,523 8,025 80,155 Non-aviation 157 9 368 19 Revenue from contracts with customers 159,795 359,239 624,148 1,175,596 Amortization of acquired contract liabilities 2,561 8,220 23,448 30,027 Total revenue 162,356 367,459 647,596 1,205,623 $ 425,994 $ 704,666 $ 1,402,886 $ 2,207,007 Contract Assets and Liabilities Contract assets primarily represent revenues recognized for performance obligations that have been satisfied or partially satisfied but for which amounts have not been billed. This typically occurs when revenue is recognized over time but the Company's contractual right to bill the customer and receive payment is conditional upon the satisfaction of additional performance obligations in the contract, such as final delivery of the product. Contract assets are recognized when the revenue associated with the contract is recognized prior to billing and derecognized when billed in accordance with the terms of the contract. The Company pools contract assets that share underlying risk characteristics and records an allowance for expected credit losses based on a combination of prior experience, current economic conditions and management’s expectations of future economic conditions, and specific collectibility matters when they arise. Contract assets are presented net of this reserve on the condensed consolidated balance sheets. For the three and nine months ended December 31, 2020 and 2019 , credit loss expense and writ e-offs related to contract assets were immaterial. Contract liabilities are recorded when customers remit contractual cash payments in advance of the Company satisfying performance obligations under contractual arrangements, including those with performance obligations to be satisfied over a period of time. Contract liabilities other than those pertaining to forward loss reserves are derecognized when or as revenue is recognized. Contract modifications can also impact contract asset and liability balances. When contracts are modified to account for changes in contract specifications and requirements, the Company considers whether the modification either creates new or changes the existing enforceable rights and obligations. Contract modifications that are for goods or services that are not distinct from the existing contract, due to the significant integration with the original good or service provided, are accounted for as if they were part of that existing contract. The effect of a contract modification to an existing contract on the transaction price and our measure of progress for the performance obligation to which it relates, is recognized as an adjustment to revenue (either as an increase in or a reduction of revenue) on a cumulative catch-up basis. When the modifications include additional performance obligations that are distinct and at relative stand-alone selling price, they are accounted for as a new contract and performance obligation, which are recognized prospectively. Contract balances are classified as assets or liabilities on a contract-by-contract basis at the end of each reporting period. The following table summarizes our contract assets and liabilities balances: December 31, 2020 March 31, 2020 Change Contract assets $ 175,099 $ 267,079 $ (91,980 ) Contract liabilities (278,690 ) (386,585 ) 107,895 Net contract liability $ (103,591 ) $ (119,506 ) $ 15,915 The Company recognized revenue due to changes in estimates associated with performance obligations satisfied or partially satisfied in previous periods of $4,577. The change in contract assets is the result of the settlement of approximately $60,802 of contract assets associated with the Gulfstream G650 wing supply chain transfer which was partially offset by Additionally, approximately $33,568 of contract assets and $13,670 of contract liabilities are classified as held for sale on the accompanying condensed consolidated balance sheet as of December 31, 2020 Performance Obligations Customers generally contract with the Company for requirements in a segment relating to a specific program, and the Company’s performance obligations consist of a wide range of engineering design services and manufactured components, as well as spare parts and repairs for OEMs. A single contract may contain multiple performance obligations consisting of both recurring and nonrecurring elements. As of December 31, 2020, the Company has the following unsatisfied, or partially unsatisfied, performance obligations that are expected to be recognized in the future as noted in the table below. The Company expects options to be exercised in addition to the amounts presented below. Total Less than 1 year 1-3 years 4-5 years More than 5 years Unsatisfied performance obligations $ 2,465,352 $ 1,330,301 $ 1,063,968 $ 71,055 $ 28

Leases

Leases	9 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	5. LEASES The components of lease expense for the three and nine months ended December 31, 2020 and 2019, are disclosed in the table below. Three Months Ended December 31, Nine Months Ended December 31, Lease Cost Financial Statement Classification 2020 2019 2020 2019 Operating lease cost Cost of sales or Selling, general and administrative expense $ 4,343 $ 5,069 $ 17,980 $ 17,829 Variable lease cost Cost of sales or Selling, general and administrative expense 2,452 2,170 7,156 5,892 Financing Lease Cost: Amortization of right-of-use assets Depreciation and amortization 1,117 1,494 3,546 4,224 Interest on lease liability Interest expense and other 410 387 1,162 1,579 Total lease cost (1) $ 8,322 $ 9,120 $ 29,844 $ 29,524 (1) Total lease cost does not include short-term leases or sublease income, both of which are immaterial. Supplemental cash flow information for the nine months ended December 31, 2020 and 2019, is disclosed in the table below. Nine Months Ended December 31, 2020 2019 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows used in operating leases $ 13,056 $ 14,046 Operating cash flows used in finance leases 1,164 1,600 Financing cash flows used in finance leases 6,170 6,516 ROU assets obtained in exchange for lease liabilities Operating leases 5,506 2,569 Finance leases 538 811 Supplemental balance sheet information related to leases as of December 31, 2020 and March 31, 2020, is disclosed in the table below. Leases Classification December 31, 2020 March 31, 2020 Assets Operating lease ROU assets Other, net Assets held for sale $ 50,434 $ 61,461 Finance lease ROU assets, cost Property and equipment, net Assets held for sale 41,757 39,461 Accumulated amortization Property and equipment, net Assets held for sale (22,217 ) (18,650 ) Finance lease ROU assets, net 19,540 20,811 Total lease assets $ 69,974 $ 82,272 Liabilities Current Operating Accrued expenses Liabilities related to assets held for sale $ 16,249 $ 13,139 Finance Current portion of long-term debt Liabilities related to assets held for sale 6,093 7,336 Noncurrent Operating Other noncurrent liabilities Liabilities related to assets held for sale 46,313 54,687 Finance Long-term debt, less current portion Liabilities related to assets held for sale 14,048 16,597 Total lease liabilities $ 82,703 $ 91,759 Information related to lease terms and discount rates as of December 31, 2020 and March 31, 2020, is disclosed in the table below. December 31, 2020 March 31, 2020 Weighted average remaining lease term (years) Operating leases 7.0 7.2 Finance leases 7.0 6.9 Weighted average discount rate Operating leases 6.3 % 6.2 % Finance leases 6.4 % 5.9 % The maturity of the Company's lease liabilities as of December 31, 2020, is disclosed in the table below. Operating leases Finance leases Total FY2021 (remaining of year) $ 7,074 $ 2,106 $ 9,180 FY2022 15,766 6,367 22,133 FY2023 10,602 3,413 14,015 FY2024 7,601 2,734 10,335 FY2025 6,909 1,361 8,270 Thereafter 31,115 9,959 41,074 Total lease payments 79,067 25,940 105,007 Less: Imputed interest (16,505 ) (5,799 ) (22,304 ) Total lease liabilities $ 62,562 $ 20,141 $ 82,703

Inventories

Inventories	9 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventories	6. INVENTORIES Inventories are stated at the lower of cost (average-cost or specific-identification methods) or market. The components of inventories are as follows: December 31, 2020 March 31, 2020 Raw materials $ 53,250 $ 32,552 Work-in-process, including manufactured and purchased components 306,589 312,953 Finished goods 55,628 50,011 Rotable assets 30,741 57,460 Total inventories $ 446,208 $ 452,976 The Company recognized an impairment loss of approximately $23,689 on certain rotable inventory that primarily arose as a result of customer fleet retirement announcements resulting from the COVID-19 pandemic. The impairment loss is included in cost of sales on the accompanying condensed consolidated statements of operations for the three and nine months ended December 31, 2020.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Long-Term Debt	7. Long-term debt consists of the following: December 31, 2020 March 31, 2020 Revolving credit facility $ — $ 400,000 Receivable securitization facility — 75,000 Finance leases 20,137 23,933 Senior secured first lien notes due 2024 700,000 — Senior secured notes due 2024 525,000 525,000 Senior notes due 2022 300,000 300,000 Senior notes due 2025 500,000 500,000 Less: debt issuance costs (25,792 ) (16,426 ) 2,019,345 1,807,507 Less: current portion 6,090 7,336 $ 2,013,255 $ 1,800,171 Revolving Credit Facility On August 17, 2020, the Company repaid the loans and other amounts outstanding under its revolving credit facility (the “Revolving Credit Facility”), which was governed by the Third Amended and Restated Credit Agreement, dated as of November 19, 2013 (as amended, the “Revolving Credit Agreement”) and terminated all commitment thereunder. The payment of $335,240 was made using a portion of the proceeds from the issuance of the Senior Secured First Lien Notes due 2024. The Company initially cash collateralized the letters of credit issued under the Revolving Credit Agreement but now have the ability to issue letters of credit under the Receivables Securitization Facility (as defined below). Receivables Securitization Program On August 17, 2020, the Company entered into amendments to its receivables securitization facility (the “Receivables Securitization Facility”). The August amendments removed the covenants that required the Company to maintain certain financial ratios. As of December 31, 2020, the maximum amount available under the Receivables Securitization Facility was $75,000, and the Company has the ability to reduce the facility amount to not less than $50,000. The actual amount available under the Receivables Securitization Facility at any point in time is dependent upon the balance of eligible accounts receivables as well as the amount of letters of credit outstanding. On September 29, 2020, the Company entered into additional amendments to the Receivables Securitization Facility. The September amendments provide the Company with enhanced liquidity options by establishing a letter of credit facility under the Receivables Securitization Facility which effectively replaces a similar limited letter of credit facility under the Revolving Credit Facility Amendment. Pursuant to the letter of credit facility, the Company may request the Receivables Securitization Facility’s administrator to issue one or more letters of credit that will expire no later than 12 months after the date of issuance, extension or renewal, as applicable. In connection with the Receivables Securitization Facility, the Company sells on a revolving basis certain eligible accounts receivable to Triumph Receivables, LLC, a wholly-owned special-purpose entity, which in turn sells a percentage ownership interest in the receivables to commercial paper conduits sponsored by financial institutions. The Company is the servicer of the trade accounts receivable under the Receivables Securitization Facility. Interest rates are based on the lesser of 0.75% or the London Interbank Offered Rate (“LIBOR”), plus a 2.50% fee on the drawn portion and 0.60% fee on the undrawn portion of the Receivables Securitization Facility. The Company secures its trade accounts receivable, which are generally non-interest-bearing, in transactions that are accounted for as borrowings pursuant to ASC 860, Transfers and Servicing The agreements governing the Receivables Securitization Facility contain restrictions and covenants, including limitations on the making of certain restricted payments; creation of certain liens; and certain corporate acts such as mergers, consolidations and the sale of all or substantially all the Company's assets. Senior Secured First Lien Notes due 2024 On August 17, 2020, the Company issued $700,000 principal amount of 8.875% Senior Secured First Lien Notes due 2024 (the “First Lien Notes”) pursuant to an indenture among the Company, the Guarantor Subsidiaries (as defined below) and U.S. Bank National Association, as trustee (the “First Lien Notes Indenture”). The First Lien Notes were sold at 100% of the principal amount and have an effective interest yield of 8.875%. Interest is payable semi-annually in cash in arrears on June 1 and December 1 of each year, commencing on December 1, 2020. In connection with the issuance of the First Lien Notes, the Company incurred approximately $13,000 of costs, which were deferred and are being amortized over the term of the First Lien Notes. The First Lien Notes and the guarantees are first lien secured obligations of the Company and the Guarantor Subsidiaries. The First Lien Notes: • rank equally in right of payment to any existing and future senior indebtedness of the Company and Guarantor Subsidiaries, including the 2022 Notes, the 2024 Notes, and the 2025 Notes, (each as defined below and collectively, the “Existing Notes”); • are effectively senior to all existing and future second lien obligations (including the 2024 Notes) and all existing and future unsecured indebtedness of the Company and the Guarantor Subsidiaries, but only to the extent of the value of the Collateral (as defined below), and after giving effect to any permitted additional first lien secured obligations and other permitted liens of senior or equal priority); • are senior in right of payment to all future subordinated indebtedness of the Company and the Guarantor Subsidiaries; • are secured by the Collateral on a pari passu basis with any future permitted additional first lien secured obligations, subject to the Collateral Trust Agreement (as defined below); • are effectively subordinated to any existing and future obligations of the Company and the Guarantor Subsidiaries that are secured by assets that do not constitute the Collateral, in each case, to the extent of the value of the assets securing such obligations; and • are structurally subordinated to all existing and future indebtedness and other liabilities of the Company’s existing and future subsidiaries that do not guarantee the First Lien Notes, including the Receivables Securitization Facility. The First Lien Notes are guaranteed on a full, senior secured, joint and several basis by each of the Company’s domestic restricted subsidiaries (the “Guarantor Subsidiaries”) that guarantees any of the Company’s Existing Notes. In the future, each of the Company’s domestic restricted subsidiaries (other than any domestic restricted subsidiary that is a receivable subsidiary) that (1) is not an immaterial subsidiary, (2) becomes a borrower under any of its material debt facilities or (3) guarantees (a) any of the Company’s indebtedness or (b) any indebtedness of the Company’s domestic restricted subsidiaries, in the case of either (a) or (b), incurred under any of the Company’s material debt facilities, will guarantee the First Lien Notes. Under certain circumstances, the guarantees may be released without action by, or consent of, the holder of the First Lien Notes. The First Lien Notes and the guarantees will be secured, subject to permitted liens, by first-priority liens on substantially all of the Company’s and the Guarantor Subsidiaries’ assets (including certain of the Company’s real estate assets), whether now owned or hereafter acquired, other than certain excluded property, which liens will secure permitted additional first lien obligations on a pari passu basis, subject to the Collateral Trust Agreement and will rank senior to those that secure the 2024 Notes (the “Collateral”). Under certain circumstances, the Collateral may be released without action by, or the consent of, the holders of the First Lien Notes. The First Lien Notes and the guarantees will not be secured by the assets of Non-Guarantor Subsidiaries (as defined below), which include the unrestricted subsidiaries to whom certain of the Company’s accounts receivables are and may in the future be sold to support borrowing under the Receivables Securitization Facility. Pursuant to an intercreditor agreement (the “Intercreditor Agreement”) between Wilmington Trust, National Association, in its capacity as the collateral trustee (the “Collateral Trustee”) and U.S. Bank National Association, in its capacity as second lien collateral agent for the 2024 Notes, the liens on the Collateral securing the First Lien Notes and all future first lien obligations will be made expressly senior to the liens securing the 2024 Notes. A collateral trust agreement (the “Collateral Trust Agreement”) among the Company, the Guarantor Subsidiaries, the Collateral Trustee and U.S. Bank National Association, in its capacity as the trustee for the First Lien Notes, will set forth therein the relative rights with respect to the Collateral as among the trustee for the First Lien Notes and certain subsequent holders of first lien obligations and covering certain other matters relating to the administration of security interests. The Collateral Trust Agreement will generally control substantially all matters related to the Collateral, including with respect to decisions, distribution of proceeds or enforcement. Pursuant to the Collateral Trust Agreement, on the issue date of the First Lien Notes the Collateral Trustee will control certain matters related to the Collateral that the Collateral Trust Agreement specifies are in its discretion. If the Company incurs certain types of additional first lien obligations, the Controlling First Lien Holders (as defined in the Collateral Trust Agreement) will have the right to control decisions relating to the Collateral that are outside the Collateral Trustee’s discretion under the Collateral Trust Agreement and the First Lien Note holders may no longer be in control of such decisions. The Company may redeem the First Lien Notes, in whole or in part, at any time or from time to time on or after February 1, 2023, at specified redemption prices, plus accrued and unpaid interest, if any, to the redemption date. At any time or from time to time prior to February 1, 2023, the Company may redeem the First Lien Notes, in whole or in part, at a redemption price equal to 100% of their principal amount plus a make whole premium, together with accrued and unpaid interest, if any, to the redemption date. In addition, the Company may redeem up to 40% of the aggregate principal amount of the outstanding First Lien Notes prior to June 1, 2023, with the net cash proceeds from certain equity offerings at a redemption price equal to 108.875% of their principal amount, together with accrued and unpaid interest, if any, to the redemption date. If the Company experiences specific kinds of changes of control, the Company is required to offer to purchase all of the First Lien Notes at a purchase price of 101% of their principal amount, plus accrued and unpaid interest, if any, to the date of purchase. The First Lien Notes Indenture contains covenants that, among other things, limit the ability of the Company and its restricted subsidiaries to: (i) incur additional indebtedness; (ii) pay dividends or make other distributions; (iii) make other restricted payments and investments; (iv) create liens; (v) incur restrictions on the ability of restricted subsidiaries to pay dividends or make certain other payments; (vi) sell assets, including capital stock of restricted subsidiaries; (vii) enter into sale and leaseback transactions; (viii) merge or consolidate with other entities; and (ix) enter into transactions with affiliates. In addition, the First Lien Notes Indenture requires, among other things, the Company to provide financial and current reports to holders of the First Lien Notes or file such reports electronically with the SEC. Furthermore, the First Lien Notes Indenture requires that the future net proceeds from certain asset sales will be required to repay the First Lien Notes at a premium of 106.656%, until the aggregate principal amount of Notes outstanding is $350,000 or less, provided that the Company may retain the first $100,000 of such net proceeds (subject to compliance with the asset sale covenants in the Company’s other outstanding indentures) or use it for certain other permitted purposes. These covenants are subject to a number of exceptions, limitations and qualifications set forth in the Indenture, as well as suspension periods in certain circumstances. Senior Secured Notes Due 2024 On September 23, 2019, the Company issued $525,000 principal amount of 6.250% Senior Secured Notes due September 15, 2024 (the "2024 Notes"). The 2024 Notes were sold at 100% of principal amount and have an effective interest yield of 6.250%. Interest on the 2024 Notes is payable semiannually in cash in arrears on March 15 and September 15 of each year. The 2024 Notes are secured by second-priority liens on all of the Company's and the Guarantor Subsidiaries' assets that secure all of the indebtedness under the Credit Facility and certain hedging and cash management obligations. Senior Notes due 2021 On September 23, 2019, the Company called all outstanding 4.875% Senior Notes due 2021 (the "2021 Notes") and discharged the 2021 Notes by irrevocably depositing with the 2021 Notes trustee sufficient funds to pay all principal and accrued interest through October 23, 2019. On October 23, 2019, the Company redeemed $375,000 principal amount of the 2021 Notes with the proceeds of the 2024 Notes. Senior Notes due 2022 On June 3, 2014, the Company issued $300,000 principal amount of 5.250% Senior Notes due June 1, 2022 (the "2022 Notes"). The 2022 Notes were sold at 100% of principal amount and have an effective interest yield of 5.250%. Interest on the 2022 Notes accrues at the rate of 5.250% per annum and is payable semiannually in cash in arrears on June 1 and December 1 of each year. Senior Notes Due 2025 On August 17, 2017, the Company issued $500,000 principal amount of 7.750% Senior Notes due August 15, 2025 (the "2025 Notes"). The 2025 Notes were sold at 100% of principal amount and have an effective interest yield of 7.750%. Interest on the 2025 Notes accrues at the rate of 7.750% per annum and is payable semiannually in cash in arrears on February 15 and August 15 of each year. Financial Instruments Not Recorded at Fair Value Carrying amounts and the related estimated fair values of the Company's long-term debt not recorded at fair value in the consolidated financial statements are as follows: December 31, 2020 March 31, 2020 Carrying Value Fair Value Carrying Value Fair Value $ 2,019,345 $ 2,053,717 $ 1,807,507 $ 1,559,455 The fair value of the long-term debt was calculated based on either interest rates available for debt with terms and maturities similar to the Company's existing debt arrangements or broker quotes on our existing debt (Level 2 inputs). Interest paid on indebtedness during the nine months ended December 31, 2020 and 2019, amounted to $79,382 and $60,885, respectively.

Earnings per Share

Earnings per Share	9 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings per Share	8. EARNINGS PER SHARE The following is a reconciliation between the weighted average outstanding shares used in the calculation of basic and diluted earnings per share: Three Months Ended December 31, Nine Months Ended December 31, (in thousands) (in thousands) 2020 2019 2020 2019 Weighted average common shares outstanding – basic 52,488 50,395 52,126 50,074 Net effect of dilutive stock options and non-vested stock (1) — — — 517 Weighted average common shares outstanding – diluted 52,488 50,395 52,126 50,591 (1) For the three and nine months ended December 31, 2020 and 2019, the shares that could potentially dilute earnings per share in the future but were not included in diluted weighted average common shares outstanding because to do so would have been anti-dilutive were immaterial.

Income Taxes

Income Taxes	9 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	9. INCOME TAXES The Company follows the Income Taxe The Company's policy is to release the tax effects from accumulated other comprehensive income when the all of the related assets or liabilities that gave rise to the accumulated other comprehensive income have been derecognized. The Company has classified uncertain tax positions as noncurrent income tax liabilities unless expected to be paid in one year. Penalties and tax-related interest expense are reported as a component of income tax expense and are not significant. As of December 31, 2020 and March 31, 2020, the total amount of unrecognized tax benefits was $18,908 and $18,965, respectively, most of which would impact the effective rate, if recognized. The Company does not anticipate that total unrecognized tax benefits will be reduced in the next 12 months. As of December 31, 2020, the Company has a valuation allowance against principally all of its net deferred tax assets given insufficient positive evidence to support the realization of the Company’s deferred tax assets. The Company intends to continue maintaining a valuation allowance on its deferred tax assets until there is sufficient positive evidence to support the reversal of all or some portion of these allowances. A reduction in the valuation allowance could result in a significant decrease in income tax expense in the period that the release is recorded. However, the exact timing and amount of the reduction in its valuation allowance is unknown at this time and will be subject to the earnings level the Company achieves during fiscal 2021 and future periods. The effective income tax rate for the three months ended December 31, 2020, was (1.0)% as compared with 21.0% for the three months ended December 31, 2019. For the three months ended December 31, 2020, the effective tax rate reflected a limitation on the recognition of tax benefits due to the full valuation allowance. The effective income tax rate for the nine months ended December 31, 2020, was (0.6)% as compared with 21.0% for the nine months ended December 31, 2019. For the nine months ended December 31, 2020, the effective tax rate reflected a limitation on the recognition of tax benefits due to the full valuation allowance. With few exceptions, the Company is no longer subject to U.S. federal, state, or local income tax examinations for fiscal years ended before March 31, 2014, or foreign income tax examinations by tax authorities for fiscal years ended before March 31, 2013. As of December 31, 2020, the Company is not subject to any ongoing income tax examinations. The Company has settled appeals for a prior state examination related to fiscal years ended March 31, 1999 through March 31, 2005.

Long-Lived Assets

Long-Lived Assets	9 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Long-Lived Assets	10. LONG-LIVED ASSETS As disclosed in Note 3, in May 2020, the Company’s Board of Directors committed to a plan (i) to sell its composites manufacturing operations located in Milledgeville, Georgia and Rayong, Thailand and (ii) to transfer the assets and certain liabilities associated with its Gulfstream G650 wing supply chain activities (as disclosed in Note 3, this transaction closed in August 2020). These planned divestitures represent the divestiture of certain assets and liabilities of an operating business within the Aerospace Structures segment that the Company has identified as an asset group pursuant to the provisions of ASC 360, Property, Plant, and Equipment In accordance with ASC 360, the Company allocated the resulting impairment to the specific long-lived assets within the asset group on a pro rata basis, except that the loss allocated to an individual long-lived asset of the group did not reduce the carrying amount of that asset below its estimated fair value. As a result, the Company recognized a total noncash impairment charge of $252,382 in the first quarter, primarily allocated to definite-lived intangible assets, which is presented as “Impairment of long-lived assets” on the condensed consolidated statements of operations.

Pension and Other Postretiremen

Pension and Other Postretirement Benefit Plans	9 Months Ended
	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Pension and Other Postretirement Benefit Plans	11. PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS The Company sponsors several defined benefit pension plans covering some of its employees. Certain employee groups are ineligible to participate in the plans or have ceased to accrue additional benefits under the plans based upon their service to the Company or years of service accrued under the defined benefit pension plans. Benefits under the defined benefit plans are based on years of service and, for most non-represented employees, on average compensation for certain years. It is the Company’s policy to fund at least the minimum amount required for all qualified plans, using actuarial cost methods and assumptions acceptable under U.S. Government regulations (and for non-U.S. plans, acceptable under local regulations), by making payments into a separate trust. The Company contributed 2,849,002 shares of common stock to this separate trust with an aggregate contribution value of approximately $40,000 on the contribution date. As a result of the contribution, the Company expects the approximately $58,000 required cash contribution for the fiscal year ending March 31, 2022, to be reduced to approximately $18,000. In addition to the defined benefit pension plans, the Company provides certain healthcare benefits for eligible retired employees. Such benefits are unfunded. No active employees are eligible for these benefits. The vast majority of eligible retirees receive a fixed-dollar benefit they can use to purchase healthcare services. A handful of eligible retirees receive traditional retiree medical benefits for which the company pays all premiums. All retirees who are eligible for these traditional benefits are Medicare-eligible. Current plan documents reserve the right to amend or terminate the plans at any time, subject to applicable collective bargaining requirements for represented employees. In accordance with the Compensation – Retirement Benefits Net Periodic Benefit Plan Costs The components of net periodic benefit costs (income) for our postretirement benefit plans are shown in the following table: Pension Benefits Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 (1) 2020 2019 (1) Components of net periodic benefit costs: Service cost $ 386 $ 577 $ 1,146 $ 1,758 Interest cost 16,107 16,073 48,294 52,162 Expected return on plan assets (34,154 ) (35,900 ) (102,395 ) (106,518 ) Amortization of prior service credits 243 (183 ) 728 (695 ) Amortization of net loss 7,812 7,632 23,417 20,651 Curtailment loss — — — 23,476 Special termination benefits — — — 11,642 Net periodic benefit income $ (9,606 ) $ (11,801 ) $ (28,810 ) $ 2,476 (1) As adjusted; refer to Note 1. Other Postretirement Benefits Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 Components of net periodic benefit costs: Service cost $ — $ — $ — $ 62 Interest cost 28 41 84 1,519 Amortization of prior service credits (1,276 ) (1,276 ) (3,828 ) (3,596 ) Amortization of gain (1,191 ) (1,186 ) (3,574 ) (5,175 ) Curtailment gain — — — (49,491 ) Net periodic benefit income $ (2,439 ) $ (2,421 ) $ (7,318 ) $ (56,681 ) (1) As adjusted; refer to Note 1.

Stockholders' Deficit

Stockholders' Deficit	9 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Stockholders' Deficit	12. STOCKHOLDERS' DEFICIT Accumulated Other Comprehensive Loss Changes in accumulated other comprehensive loss ("AOCI") by component for the three and nine months ended December 31, 2020 and 2019, were as follows: Currency Translation Adjustment Unrealized Gains and Losses on Derivative Instruments Defined Benefit Pension Plans and Other Postretirement Benefits Total (2) September 30, 2020 $ (53,844 ) $ 28 $ (671,570 ) $ (725,386 ) AOCI before reclassifications 12,637 1,878 — 14,515 Amounts reclassified from AOCI — 437 4,265 (3) 4,702 Net current period OCI 12,637 2,315 4,265 19,217 December 31, 2020 $ (41,207 ) $ 2,343 $ (667,305 ) $ (706,169 ) September 30, 2019 (1) $ (57,516 ) $ (2,527 ) $ (532,554 ) $ (592,597 ) AOCI before reclassifications 11,074 4,581 — 15,655 Amounts reclassified from AOCI — (80 ) 4,387 (3) 4,307 Net current period OCI 11,074 4,501 4,387 19,962 December 31, 2019 (1) $ (46,442 ) $ 1,974 $ (528,167 ) $ (572,635 ) March 31, 2020 (1) $ (62,045 ) $ (4,303 ) $ (680,100 ) $ (746,448 ) AOCI before reclassifications 20,838 8,308 — 29,146 Amounts reclassified from AOCI — (1,662 ) 12,795 (3) 11,133 Net current period OCI 20,838 6,646 12,795 40,279 December 31, 2020 $ (41,207 ) $ 2,343 $ (667,305 ) $ (706,169 ) March 31, 2019 (1) $ (48,606 ) $ (1,130 ) $ (466,275 ) $ (516,011 ) AOCI before reclassifications 2,164 4,921 (122,971 ) (115,886 ) Amounts reclassified from AOCI — (1,817 ) 61,079 (3) 59,262 Net current period OCI 2,164 3,104 (61,892 ) (56,624 ) December 31, 2019 (1) $ (46,442 ) $ 1,974 $ (528,167 ) $ (572,635 ) (1) As adjusted; refer to Note 1. (2) Net of tax. (3) Includes amortization of actuarial losses and recognized prior service (credits) costs, which are included in net periodic pension cost of which a portion is allocated to production as inventoried costs. Net periodic pension cost is presented in cost of sales and non-service defined benefit income on the accompanying condensed consolidated statements of operations. Refer to Note 11 for additional disclosure regarding our postretiremend benefit plans.

Segments

Segments	9 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segments	13. The Company reports financial performance based on the following two reportable segments: Systems & Support and Aerospace Structures. The Company’s reportable segments are aligned with how the business is managed, and the Company's views of the markets it serves. The Chief Operating Decision Maker (the "CODM") evaluates performance and allocates resources based upon review of segment information. The CODM utilizes earnings before interest, income taxes, depreciation and amortization, and pension (“Adjusted EBITDAP”) as a primary measure of segment profitability to evaluate performance of its segments and allocate resources. Segment Adjusted EBITDAP is total segment revenue reduced by operating expenses (less depreciation and amortization) identifiable with that segment. Corporate includes general corporate administrative costs and any other costs not identifiable with one of the Company’s segments. The Company does not accumulate net sales information by product or service or groups of similar products and services, and therefore the Company does not disclose net sales by product or service because to do so would be impracticable. Selected financial information for each reportable segment is as follows: Three Months Ended December 31, 2020 Total Corporate & Eliminations Systems & Support Aerospace Structures Net sales to external customers $ 425,994 $ — $ 263,638 $ 162,356 Intersegment sales (eliminated in consolidation) — (536 ) 482 54 Segment profit and reconciliation to consolidated income before income taxes: Adjusted EBITDAP 61,407 — 46,746 14,661 Reconciliation of segment profit to income (loss) before income taxes Depreciation and amortization (22,119 ) (989 ) (8,353 ) (12,777 ) Interest expense and other, net (44,881 ) Corporate expenses (8,483 ) Share-based compensation expense (3,679 ) Loss on sale of assets and businesses (45,273 ) Amortization of acquired contract liabilities 6,867 Non-service defined benefit income 12,432 Impairment of rotable inventory (23,689 ) Loss before income taxes (67,418 ) Total capital expenditures $ 6,184 $ 158 $ 2,308 $ 3,718 Total assets $ 2,401,922 $ 451,824 $ 1,463,017 $ 487,081 Three Months Ended December 31, 2019 (1) Total Corporate & Eliminations Systems & Support Aerospace Structures Net sales to external customers $ 704,666 $ — $ 337,207 $ 367,459 Intersegment sales (eliminated in consolidation) — (3,230 ) 1,717 1,513 Segment profit and reconciliation to consolidated income before income taxes: Adjusted EBITDAP 89,272 — 57,132 32,140 Reconciliation of segment profit to income (loss) before income taxes Depreciation and amortization (29,843 ) (847 ) (8,075 ) (20,921 ) Interest expense and other, net (33,178 ) Corporate expenses (13,848 ) Share-based compensation expense (2,955 ) Loss on sale of assets and businesses (60,019 ) Amortization of acquired contract liabilities 16,597 Non-service defined benefit income 14,799 Union represented employee incentives (1,400 ) Legal judgment gain, net 3,857 Loss before income taxes (16,718 ) Total capital expenditures $ 10,255 $ 416 $ 3,929 $ 5,910 Nine Months Ended December 31, 2020 Total Corporate & Eliminations Systems & Support Aerospace Structures Net sales to external customers $ 1,402,886 $ — $ 755,290 $ 647,596 Intersegment sales (eliminated in consolidation) — (4,357 ) 2,888 1,469 Segment profit and reconciliation to consolidated income before income taxes: Adjusted EBITDAP 131,067 — 110,983 20,084 Reconciliation of segment profit to income (loss) before income taxes Depreciation and amortization (72,819 ) (2,652 ) (24,830 ) (45,337 ) Interest expense and other, net (132,344 ) Corporate expenses (42,027 ) Share-based compensation expense (9,086 ) Loss on sale of assets and businesses (46,020 ) Amortization of acquired contract liabilities 35,017 Non-service defined benefit income 37,275 Impairment of rotable inventory (23,689 ) Impairment of long-lived assets (252,382 ) Loss before income taxes (375,008 ) Total capital expenditures $ 18,988 $ 801 $ 11,819 $ 6,368 Nine Months Ended December 31, 2019 (1) Total Corporate & Eliminations Systems & Support Aerospace Structures Net sales to external customers $ 2,207,007 $ — $ 1,001,384 $ 1,205,623 Intersegment sales (eliminated in consolidation) — (9,224 ) 4,118 5,106 Segment profit and reconciliation to consolidated income before income taxes: Adjusted EBITDAP 250,126 — 162,008 88,118 Reconciliation of segment profit to income (loss) before income taxes Depreciation and amortization (104,112 ) (2,533 ) (24,314 ) (77,265 ) Interest expense and other, net (96,069 ) Corporate expenses (42,709 ) Share-based compensation expense (8,245 ) Loss on sale of assets and businesses (55,190 ) Amortization of acquired contract liabilities 56,153 Non-service defined benefit income 56,025 Union represented employee incentives (7,071 ) Legal judgment gain, net 9,257 Income before income taxes 58,165 Total capital expenditures $ 27,250 $ 980 $ 12,355 $ 13,915 (1) As adjusted; refer to Note 1. During the three months ended December 31, 2020 and 2019, the Company had foreign sales of $78,440 and $164,832, respectively. During the nine months ended December 31, 2020 and 2019, the Company had foreign sales of $267,370 and $526,130, respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Dec. 31, 2020
Commitments And Contingencies [Abstract]
Commitments and Contingencies	14. In the ordinary course of business, the Company is involved in disputes, claims and lawsuits with employees, suppliers and customers, as well as governmental and regulatory inquiries, that it deems to be immaterial. Some may involve claims or potential claims of substantial damages, fines, penalties or injunctive relief. While the Company cannot predict the outcome of any pending or future litigation or proceeding and no assurances can be given, the Company does not believe that any pending matter will have a material effect, individually or in the aggregate, on its financial position or results of operations. As the Company completes its restructuring plans as disclosed in Note 15, including the disposal of certain facilities, the Company may be exposed to additional costs such as environmental remediation obligations, lease termination costs, or supplier claims which may have a material effect on its financial position or results of operations when such matters arise and a reasonable estimate of the costs can be made.

Restructuring

Restructuring	9 Months Ended
	Dec. 31, 2020
Restructuring And Related Activities [Abstract]
Restructuring	15. As disclosed in the Company's Form 10-K for the fiscal year ended March 31, 2020, during the fiscal years ended March 31, 2017 and 2016, the Company committed to restructuring plans involving certain of its businesses, as well as the consolidation of certain of its facilities. With the exception of certain consolidations to be completed in future years, these plans were substantially complete as of March 31, 2020. During the nine months ended December 31, 2020, the Company incurred costs of $5,725, $20,580, and $6,442, within Systems & Support, Aerospace Structures, and its corporate headquarters, respectively, for total restructuring costs of $32,747 associated with new restructuring plans. Of the restructuring costs within Aerospace Structures, approximately $13,097 pertained to facility closures with the remainder primarily related to postemployment benefits arising from reductions in force and third-party consulting costs. The restructuring costs within Systems & Support and Corporate are primarily related to postemployment benefits arising from reductions in force and third-party consulting costs. We estimate that we will incur consolidated restructuring costs of approximately $34,000 for the fiscal year ended March 31, 2021, with costs being incurred in each of our segments for third-party consulting costs and severance, primarily related to our cost-reduction initiatives.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Standards Recently Implemented and Standards Issued Not Yet Implemented	Standards Recently Implemented Adoption of ASU 2016-13 In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. The Company adopted ASU 2018-13 effective April 1, 2020 , and the adoption did not have a significant impact on its consolidated financial statement disclosures. Standards Issued Not Yet Implemented In August 2018, the FASB issued ASU 2018-14, Compensation—Retirement Benefits—Defined Benefit Plans—General (Subtopic 715-20): Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans Impact of Change in Accounting Principle Effective April 1, 2020, the Company changed its method of accounting for the determination of the market-related value of assets (“MRVA”) for a class of assets (fixed income securities) within the qualified U.S. defined benefit plan (the “Plan”) which is used in determining the expected return on asset component of net periodic benefit income. This class of assets is comprised solely of the fixed income securities asset class held in the portfolio for the Plan, which provides a natural hedge (liability-hedging assets) against the changes in the recorded amount of net periodic pension cost. Refer to Note 15 in the Company’s Form 10-K for the fiscal year ended March 31, 2020, for its fair value disclosure by asset classification. The Company’s previous method of accounting was to calculate the MRVA for all the Plan’s assets recognizing investment gains and losses into the MRVA over a five-year period. T he Company has changed its method of accounting and elected to use the fair value of our fixed income assets, which represent approximately 44% of the Plan’s assets, to determine the MRVA beginning in the second quarter of fiscal 2021. This change in accounting principle is preferable as it results in an expected return on asset component of net periodic benefit income that more accurately reflects the changes in the fair values of the fixed income securities. No change is being made to the accounting principle for the other classes of pension assets, which represent the remaining 56% of the pension asset five-year The change in accounting principle requires retrospective application and prospective disclosure. The Company applied the change effective April 1, 2020, and recorded a cumulative adjustment to equity as of the earliest period presented. The tables below represent the impact of this change on the condensed consolidated statements of operations (including earnings per share) and the condensed consolidated statements of comprehensive (loss) income for the periods presented below. The change in accounting principle had no impact on the condensed consolidated statements of cash flows for these periods. The tables below represent the impact of the change in accounting principle on the condensed consolidated statement of operations and the condensed consolidated statements of comprehensive loss for the three and nine months ended December 31, 2020. Three Months Ended Nine Months Ended As Reported (With Change), December 31, 2020 Impact of Change Without Change, December 31, 2020 As Reported (With Change), December 31, 2020 Impact of Change Without Change, December 31, 2020 Non-service defined benefit income $ (12,432 ) $ (1,528 ) $ (13,960 ) $ (37,275 ) $ (4,584 ) $ (41,859 ) Loss before income taxes (67,418 ) 1,528 (65,890 ) (375,008 ) 4,584 (370,424 ) Income tax expense 698 - 698 2,383 - 2,383 Net loss $ (68,116 ) $ 1,528 $ (66,588 ) $ (377,391 ) $ 4,584 $ (372,807 ) Net Loss per share - basic & diluted Basic $ (1.30 ) $ 0.03 $ (1.27 ) $ (7.24 ) $ 0.09 $ (7.15 ) Diluted $ (1.30 ) $ 0.03 $ (1.27 ) $ (7.24 ) $ 0.09 $ (7.15 ) Defined benefit pension plans and other postretirement benefits: Total defined benefit pension plans and other postretirement benefits, net of taxes $ 4,265 $ (1,528 ) $ 2,737 $ 12,795 $ (4,584 ) $ 8,211 Total other comprehensive income $ 19,217 $ (1,528 ) $ 17,689 $ 40,279 $ (4,584 ) $ 35,695 Comprehensive loss $ (48,899 ) $ - $ (48,899 ) $ (337,112 ) $ - $ (337,112 ) The table below represents the impact of the change in accounting principle on the condensed consolidated balance sheet as of December 31, 2020. Stockholders' deficit: As Reported (With Change), December 31, 2020 Impact of Change Without Change, December 31, 2020 Accumulated other comprehensive loss $ (706,169 ) $ (31,604 ) $ (737,773 ) Accumulated deficit $ (1,180,872 ) $ 31,604 $ (1,149,268 ) Total stockholders' deficit $ (1,069,830 ) $ - $ (1,069,830 ) The tables below represent the impact of the change in accounting principle on the condensed consolidated statement of operations and the condensed consolidated statements of comprehensive income (loss) for the three and nine months ended December 31, 2019. Three Months Ended Nine Months Ended As Previously Reported, December 31, 2019 Impact of Change As Reported, December 31, 2019 As Previously Reported, December 31, 2019 Impact of Change As Reported, December 31, 2019 Non-service defined benefit income $ (13,989 ) (810 ) $ (14,799 ) $ (57,280 ) 1,255 $ (56,025 ) (Loss) income before income taxes (17,528 ) 810 (16,718 ) 59,420 (1,255 ) 58,165 Income tax (benefit) expense (3,682 ) 170 (3,512 ) 12,477 (264 ) 12,213 Net (loss) income $ (13,846 ) $ 640 $ (13,206 ) $ 46,943 $ (991 ) $ 45,952 Net (Loss) Income per share - basic & diluted Basic $ (0.27 ) $ 0.01 $ (0.26 ) $ 0.94 $ (0.02 ) $ 0.92 Diluted $ (0.27 ) $ 0.01 $ (0.26 ) $ 0.93 $ (0.02 ) $ 0.91 Defined benefit pension plans and other postretirement benefits (expense): Total defined benefit pension plans and other postretirement benefits (expense), net of taxes $ 5,027 $ (640 ) $ 4,387 $ (62,883 ) $ 991 $ (61,892 ) Total other comprehensive income (loss) $ 20,602 $ (640 ) $ 19,962 $ (57,615 ) $ 991 $ (56,624 ) Comprehensive income (loss) $ 6,756 $ - $ 6,756 $ (10,672 ) $ - $ (10,672 ) The table below represents the impact of the change in accounting principle on the condensed consolidated balance sheet as of March 31, 2020. As Previously Reported, March 31, 2020 Impact of Change As Reported, March 31, 2020 Stockholders' deficit: Accumulated other comprehensive loss $ (719,428 ) $ (27,020 ) $ (746,448 ) Accumulated deficit (830,501 ) 27,020 (803,481 ) Total stockholders' deficit $ (781,264 ) $ - $ (781,264 )
Use of Estimates	Use of Estimates The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Actual results could differ from those estimates.
Revenue Recognition and Contract Balances	Revenue Recognition and Contract Balances The Company's revenue is principally from contracts with customers to provide design, development, manufacturing, and support services associated with specific customer programs. The Company regularly enters into long-term master supply agreements that establish general terms and conditions and may define specific program requirements. Many agreements include clauses that provide sole supplier status to the Company for the duration of the program’s life. Purchase orders (or authorizations to proceed) are issued pursuant to the master supply agreements. Additionally, a majority of the Company’s agreements with customers include options for future purchases. Such options primarily reduce the administrative effort of issuing subsequent purchase orders and do not represent material rights granted to customers. The Company generally enters into agreements directly with its customers and is the principal in all current contracts. The identification of a contract with a customer for purposes of accounting and financial reporting requires an evaluation of the terms and conditions of agreements to determine whether presently enforceable rights and obligations exist. Management considers a number of factors when making this evaluation that include, but are not limited to, the nature and substance of the business exchange, the specific contractual terms and conditions, the promised products and services, the termination provisions in the contract, as well as the nature and execution of the customer’s ordering process and how the Company is authorized to perform work. Generally, presently enforceable rights and obligations are not created until a purchase order is issued by a customer for a specified number of units of product or services. Therefore, the issuance of a purchase order is generally the point at which a contract is identified for accounting and financial reporting purposes. Management identifies the promises to the customer. Promises are generally explicitly stated in each contract, but management also evaluates whether any promises are implied based on the terms of the agreement, past business practice, or other facts and circumstances. Each promise is evaluated to determine if it is a performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service. The Company considers a number of factors when determining whether a promise is a distinct performance obligation, including whether the customer can benefit from the good or service on its own or together with other resources that are readily available to the customer, whether the Company provides a significant service of integrating goods or services to deliver a combined output to the customer, or whether the goods or services are highly interdependent. The Company’s performance obligations consist of a wide range of engineering design services and manufactured components, as well as spare parts and repairs for OEMs. The transaction price for a contract reflects the consideration the Company expects to receive for fully satisfying the performance obligations in the contract. Typically, the transaction price consists solely of fixed consideration but may include variable consideration for contractual provisions such as unpriced contract modifications, cost-sharing provisions, and other receipts or payments to customers. The Company identifies and estimates variable consideration, typically at the most likely amount the Company expects to receive from its customers. Variable consideration is only included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized for the contract will not occur, or when the uncertainty associated with the variable consideration is resolved. The Company's contracts with customers generally require payment under normal commercial terms after delivery with payment typically required within 30 to 120 days of delivery. However, a subset of the Company’s current contracts includes significant financing components because the timing of the transfer of the underlying products and services under contract are at the customers’ discretion. For these contracts, the Company adjusts the transaction price to reflect the effects of the time value of money. The Company generally is not subject to collecting sales tax and has made an accounting policy election to exclude from the transaction price any sales and other similar taxes collected from customers. As a result, any such collections are accounted for on a net basis. The total transaction price is allocated to each of the identified performance obligations using the relative stand-alone selling price. The objective of the allocation is to reflect the consideration that the Company expects to receive in exchange for the products or services associated with each performance obligation. Stand-alone selling price is the price at which the Company would sell a promised good or service separately to a customer. Stand-alone selling prices are established at contract inception, and subsequent changes in transaction price are allocated on the same basis as at contract inception. When stand-alone selling prices for the Company’s products and services are not observable, the Company uses either the “Expected Cost Plus a Margin” or "Adjusted Market Assessment" approaches to estimate stand-alone selling price. Expected costs are typically derived from the available periodic forecast information. Revenue is recognized when or as control of promised products or services transfers to a customer and is recognized at the amount allocated to each performance obligation associated with the transferred products or services. Service sales, principally representing repair, maintenance, and engineering activities are recognized over the contractual period or as services are rendered. Sales under long-term contracts with performance obligations satisfied over time are recognized using either an input or output method. The Company recognizes revenue over time as it performs on these contracts because of the continuous transfer of control to the customer as represented by contractual terms that entitle the Company to the reimbursement of costs plus a reasonable profit for work performed to manufacture products for which the Company has no alternate use or for work performed on a customer-owned asset. With control transferring over time, revenue is recognized based on the extent of progress toward completion of the performance obligation. The Company generally uses the cost-to-cost input method of progress for its contracts because it best depicts the transfer of control to the customer that occurs as work progresses. Under the cost-to-cost method, the extent of progress toward completion is measured based on the proportion of costs incurred to date to the total estimated costs at completion of the performance obligation. The Company reviews its cost estimates on contracts on a periodic basis, or when circumstances change and warrant a modification to a previous estimate. Cost estimates are largely based on negotiated or estimated purchase contract terms, historical performance trends and other economic projections. Significant factors that influence these estimates include inflationary trends, technical and schedule risk, internal and subcontractor performance trends, business volume assumptions, asset utilization, and anticipated labor agreements. Revenue and cost estimates are regularly monitored and revised based on changes in circumstances. Impacts from changes in estimates of net sales and cost of sales are recognized on a cumulative catch-up basis, which recognizes in the current period the cumulative effect of the changes on current and prior periods based on a performance obligation’s percentage of completion. Forward loss reserves for anticipated losses on long-term contracts are recorded in full when such losses become evident, to the extent required, and are included in contract liabilities on the accompanying condensed consolidated balance sheets. The Company believes that the accounting estimates and assumptions made by management are appropriate given the increased uncertainties surrounding the severity and duration of the impacts of the COVID-19 pandemic; however, actual results could differ materially from those estimates. For the three months ended December 31, 2020, cumulative catch-up adjustments resulting from changes in contract values and estimated costs that arose during the fiscal year decreased revenue, operating loss, net loss and loss per share by approximately ($37), $3,688, $3,688, and $0.07, respectively. For the three months ended December 31, 2019, cumulative catch-up adjustments resulting from changes in estimates increased net sales by approximately $4,722 and decreased operating income, net income, and earnings per share by approximately ($210), ($166), and $0.00, respectively. For the nine months ended December 31, 2020, cumulative catch-up adjustments resulting from changes in contract values and estimated costs that arose during the fiscal year increased revenue and decreased operating loss, net loss and loss per share by approximately $4,577, $19,349, $19,349, and $0.37, respectively. For the nine months ended December 31, 2019, cumulative catch-up adjustments resulting from changes in estimates increased net sales by approximately $2,347 and decreased operating income, net income, and earnings per share by approximately ($16,393), ($12,950), and ($0.26), respectively. Revenues for performance obligations that are not recognized over time are recognized at the point in time when control transfers to the customer. For performance obligations that are satisfied at a point in time, the Company evaluates the point in time when the customer can direct the use of and obtain the benefits from the products and services. Generally, the shipping terms determine the point in time when control transfers to customers. Shipping and handling activities are not considered performance obligations and related costs are included in cost of sales as incurred. Differences in the timing of revenue recognition and contractual billing and payment terms result in the recognition contract assets and liabilities. Refer to Note 4 for further discussion. In connection with several prior acquisitions, the Company assumed existing long-term contracts. Based on review of these contracts at the acquisition date, the Company concluded that the terms of certain contracts were either more or less favorable than could be realized in market transactions as of the date of the acquisition. As a result, the Company recognized acquired contract liabilities, net of acquired contract assets as of the acquisition date of each respective acquisition, based on the present value of the difference between the contractual cash flows of the executory contracts and the estimated cash flows had the contracts been executed at the acquisition date. The liabilities principally relate to long-term contracts that were initially executed several years prior to the respective acquisition. The Company measured these net liabilities in the year they were acquired under the measurement provisions of Accounting Standards Codification (“ASC”) 820, Fair Value Measurement
Trade and Other Receivables, net	Trade and Other Receivables, net Trade and other receivables are recorded net of an allowance for expected credit losses. Trade and other receivables include amounts billed and currently due from customers and amounts retained by the customer pending contract completion. The Company performs ongoing credit evaluations of its customers and generally does not require collateral. The Company pools receivables that share underlying risk characteristics and records the allowance for expected credit losses based on a combination of prior experience, current economic conditions and management’s expectations of future economic conditions, and specific collectibility matters when they arise. The Company writes off balances against the allowance for expected credit losses when collectibility is deemed remote. The Company's trade and other receivables are exposed to credit risk; however, the risk is limited due to the diversity of the customer base. For the three and nine months ended December 31, 2020 and 2019, credit loss expense and write-offs were immaterial.
Leases	Leases The Company leases office space, manufacturing facilities, land, vehicles, and equipment. The Company determines if an agreement is or contains a lease at the lease inception date and recognizes right-of-use (“ROU”) assets and lease liabilities at the lease commencement date. A ROU asset and corresponding lease liability are not recorded for leases with an initial term of 12 months or less (“short-term leases”). ROU assets represent the Company's right to use an underlying asset during the lease term, and lease liabilities represent the Company's obligation to make lease payments arising from the lease. The determination of the length of lease terms is affected by options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. The existence of significant economic incentive is the primary consideration when assessing whether the Company is reasonably certain of exercising an option in a lease. Both finance and operating lease ROU assets and liabilities are recognized at commencement date and measured as the present value of lease payments to be made over the lease term. As the interest rate implicit in the lease is not readily available for most of the Company's leases, the Company uses its estimated incremental borrowing rate in determining the present value of lease payments. The estimated incremental borrowing rate is derived from information available at the lease commencement date. The lease ROU asset recognized at commencement is adjusted for any lease payments related to initial direct costs, prepayments, and lease incentives. For operating leases, lease expense is recognized on a straight-line basis over the lease term. For finance leases, lease expense comprises the amortization of the ROU assets recognized on a straight-line basis generally over the shorter of the lease term or the estimated useful life of the underlying asset and interest on the lease liability. Variable lease payments not dependent on a rate or index are recognized when the event, activity, or circumstance in the lease agreement upon which those payments are contingent is probable of occurring and are presented in the same line of the consolidated balance sheet as the rent expense arising from fixed payments. The Company has lease agreements with lease and non-lease components. Non-lease components are combined with the related lease components and accounted for as lease components for all classes of underlying assets.
Concentration of Credit Risk	Concentration of Credit Risk The Company’s trade and other accounts receivable are exposed to credit risk. However, the risk is limited due to the diversity of the customer base and the customer base’s wide geographical area. Trade accounts receivable from The Boeing Company ("Boeing") (representing commercial, military and space) represented approximately 19% and 21% of total trade accounts receivable as of December 31, 2020 and March 31, 2020, respectively. Trade and other accounts receivable from Bombardier Inc. ("Bombardier") include receivables from transition services and represented approximately 2% and 16% as of December 31, 2020 and March 31, 2020, respectively. The Company had no other concentrations of credit risk of more than 10%. Sales to Boeing for the nine months ended December 31, 2020, were $528,263, or 38% of net sales, of which $164,520 and $363,743 were from Systems & Support and Aerospace Structures, respectively. Sales to Boeing for the nine months ended December 31, 2019, were $742,495, or 34% of net sales, of which $189,854 and $552,641 were from Systems & Support and Aerospace Structures, respectively. The percentage increase in sales to Boeing as compared with the prior period is driven entirely by military sales. Sales to Gulfstream Aerospace Corporation (“Gulfstream”) for the nine months ended December 31, 2020, were $100,364, or 7% of net sales, of which $2,166 and $98,197 were from Systems & Support and Aerospace Structures, respectively. Sales to Gulfstream for the nine months ended December 31, 2019, were $268,917, or 12% of net sales, of which $2,497 and $266,421 were from Systems & Support and Aerospace Structures, respectively. No other single customer accounted for more than 10% of the Company’s net sales. However, the loss of any significant customer, including Boeing and Gulfstream, could have a material adverse effect on the Company and its operating subsidiaries.
Fair Value Measurements	Fair Value Measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. When determining fair value measurements for assets and liabilities required to be recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and also considers assumptions that market participants would use when pricing an asset or liability. The fair value hierarchy has three levels of inputs that may be used to measure fair value: Level 1—Unadjusted quoted prices in active markets for identical assets or liabilities; Level 2—Unadjusted quoted prices in active markets for similar assets or liabilities, or unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable for the asset or liability; and Level 3—Unobservable inputs for the asset or liability. The Company has applied fair value measurements when measuring the impairment of assets held for sale (see Note 3), when measuring the long-lived asset impairment in the current period (see Note 10), and to its pension and postretirement plan assets (see Note 11).
Supplemental Cash Flow Information	Supplemental Cash Flow Information For the nine months ended December 31, 2020, the Company paid $2,474 for income taxes, net of income tax refunds received. For the nine months ended December 31, 2019, the Company paid $4,370 for income taxes, net of income tax refunds received.

Background and Basis of Prese_2

Background and Basis of Presentation (Tables)	9 Months Ended
	Dec. 31, 2020
Change in Accounting Principle [Member]
Schedule of Impact of Change in Accounting Principle on Condensed Consolidated Financial Statements	The tables below represent the impact of the change in accounting principle on the condensed consolidated statement of operations and the condensed consolidated statements of comprehensive loss for the three and nine months ended December 31, 2020. Three Months Ended Nine Months Ended As Reported (With Change), December 31, 2020 Impact of Change Without Change, December 31, 2020 As Reported (With Change), December 31, 2020 Impact of Change Without Change, December 31, 2020 Non-service defined benefit income $ (12,432 ) $ (1,528 ) $ (13,960 ) $ (37,275 ) $ (4,584 ) $ (41,859 ) Loss before income taxes (67,418 ) 1,528 (65,890 ) (375,008 ) 4,584 (370,424 ) Income tax expense 698 - 698 2,383 - 2,383 Net loss $ (68,116 ) $ 1,528 $ (66,588 ) $ (377,391 ) $ 4,584 $ (372,807 ) Net Loss per share - basic & diluted Basic $ (1.30 ) $ 0.03 $ (1.27 ) $ (7.24 ) $ 0.09 $ (7.15 ) Diluted $ (1.30 ) $ 0.03 $ (1.27 ) $ (7.24 ) $ 0.09 $ (7.15 ) Defined benefit pension plans and other postretirement benefits: Total defined benefit pension plans and other postretirement benefits, net of taxes $ 4,265 $ (1,528 ) $ 2,737 $ 12,795 $ (4,584 ) $ 8,211 Total other comprehensive income $ 19,217 $ (1,528 ) $ 17,689 $ 40,279 $ (4,584 ) $ 35,695 Comprehensive loss $ (48,899 ) $ - $ (48,899 ) $ (337,112 ) $ - $ (337,112 ) The table below represents the impact of the change in accounting principle on the condensed consolidated balance sheet as of December 31, 2020. Stockholders' deficit: As Reported (With Change), December 31, 2020 Impact of Change Without Change, December 31, 2020 Accumulated other comprehensive loss $ (706,169 ) $ (31,604 ) $ (737,773 ) Accumulated deficit $ (1,180,872 ) $ 31,604 $ (1,149,268 ) Total stockholders' deficit $ (1,069,830 ) $ - $ (1,069,830 ) The tables below represent the impact of the change in accounting principle on the condensed consolidated statement of operations and the condensed consolidated statements of comprehensive income (loss) for the three and nine months ended December 31, 2019. Three Months Ended Nine Months Ended As Previously Reported, December 31, 2019 Impact of Change As Reported, December 31, 2019 As Previously Reported, December 31, 2019 Impact of Change As Reported, December 31, 2019 Non-service defined benefit income $ (13,989 ) (810 ) $ (14,799 ) $ (57,280 ) 1,255 $ (56,025 ) (Loss) income before income taxes (17,528 ) 810 (16,718 ) 59,420 (1,255 ) 58,165 Income tax (benefit) expense (3,682 ) 170 (3,512 ) 12,477 (264 ) 12,213 Net (loss) income $ (13,846 ) $ 640 $ (13,206 ) $ 46,943 $ (991 ) $ 45,952 Net (Loss) Income per share - basic & diluted Basic $ (0.27 ) $ 0.01 $ (0.26 ) $ 0.94 $ (0.02 ) $ 0.92 Diluted $ (0.27 ) $ 0.01 $ (0.26 ) $ 0.93 $ (0.02 ) $ 0.91 Defined benefit pension plans and other postretirement benefits (expense): Total defined benefit pension plans and other postretirement benefits (expense), net of taxes $ 5,027 $ (640 ) $ 4,387 $ (62,883 ) $ 991 $ (61,892 ) Total other comprehensive income (loss) $ 20,602 $ (640 ) $ 19,962 $ (57,615 ) $ 991 $ (56,624 ) Comprehensive income (loss) $ 6,756 $ - $ 6,756 $ (10,672 ) $ - $ (10,672 ) The table below represents the impact of the change in accounting principle on the condensed consolidated balance sheet as of March 31, 2020. As Previously Reported, March 31, 2020 Impact of Change As Reported, March 31, 2020 Stockholders' deficit: Accumulated other comprehensive loss $ (719,428 ) $ (27,020 ) $ (746,448 ) Accumulated deficit (830,501 ) 27,020 (803,481 ) Total stockholders' deficit $ (781,264 ) $ - $ (781,264 )

Revenue Recognition and Contr_2

Revenue Recognition and Contracts with Customers (Tables)	9 Months Ended
	Dec. 31, 2020
Change In Contract With Customer Asset And Liability [Abstract]
Disaggregation of Revenue	The following table shows disaggregated net sales satisfied overtime and at a point in time (excluding intercompany sales) for the three and nine months ended December 31, 2020 and 2019: Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 Systems & Support Satisfied over time $ 118,813 $ 135,229 $ 324,968 $ 403,825 Satisfied at a point in time 140,519 193,601 418,753 571,433 Revenue from contracts with customers 259,332 328,830 743,721 975,258 Amortization of acquired contract liabilities 4,306 8,377 11,569 26,126 Total revenue 263,638 337,207 755,290 1,001,384 Aerospace Structures Satisfied over time $ 148,526 $ 330,657 $ 596,145 $ 1,075,141 Satisfied at a point in time 11,269 28,582 28,003 100,455 Revenue from contracts with customers 159,795 359,239 624,148 1,175,596 Amortization of acquired contract liabilities 2,561 8,220 23,448 30,027 Total revenue 162,356 367,459 647,596 1,205,623 $ 425,994 $ 704,666 $ 1,402,886 $ 2,207,007 The following table shows disaggregated net sales by end market (excluding intercompany sales) for the three and nine months ended December 31, 2020 and 2019: Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 Systems & Support Commercial aerospace $ 92,529 $ 192,232 $ 280,102 $ 561,815 Military 145,168 105,860 396,672 309,735 Business jets 7,802 10,776 26,884 45,280 Regional 5,231 11,310 18,218 33,434 Non-aviation 8,602 8,652 21,845 24,994 Revenue from contracts with customers 259,332 328,830 743,721 975,258 Amortization of acquired contract liabilities 4,306 8,377 11,569 26,126 Total revenue $ 263,638 $ 337,207 $ 755,290 $ 1,001,384 Aerospace Structures Commercial aerospace $ 109,929 $ 208,943 $ 372,249 $ 681,471 Military 31,670 27,394 105,365 83,773 Business jets 18,039 98,370 138,141 330,178 Regional — 24,523 8,025 80,155 Non-aviation 157 9 368 19 Revenue from contracts with customers 159,795 359,239 624,148 1,175,596 Amortization of acquired contract liabilities 2,561 8,220 23,448 30,027 Total revenue 162,356 367,459 647,596 1,205,623 $ 425,994 $ 704,666 $ 1,402,886 $ 2,207,007
Summary of Contract Assets and Liabilities Balances	Contract balances are classified as assets or liabilities on a contract-by-contract basis at the end of each reporting period. The following table summarizes our contract assets and liabilities balances: December 31, 2020 March 31, 2020 Change Contract assets $ 175,099 $ 267,079 $ (91,980 ) Contract liabilities (278,690 ) (386,585 ) 107,895 Net contract liability $ (103,591 ) $ (119,506 ) $ 15,915
Schedule of Performance Obligations that are Expected to Be Recognized in Future	As of December 31, 2020, the Company has the following unsatisfied, or partially unsatisfied, performance obligations that are expected to be recognized in the future as noted in the table below. The Company expects options to be exercised in addition to the amounts presented below. Total Less than 1 year 1-3 years 4-5 years More than 5 years Unsatisfied performance obligations $ 2,465,352 $ 1,330,301 $ 1,063,968 $ 71,055 $ 28

Leases (Tables)

Leases (Tables)	9 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of Components Lease Expense	The components of lease expense for the three and nine months ended December 31, 2020 and 2019, are disclosed in the table below. Three Months Ended December 31, Nine Months Ended December 31, Lease Cost Financial Statement Classification 2020 2019 2020 2019 Operating lease cost Cost of sales or Selling, general and administrative expense $ 4,343 $ 5,069 $ 17,980 $ 17,829 Variable lease cost Cost of sales or Selling, general and administrative expense 2,452 2,170 7,156 5,892 Financing Lease Cost: Amortization of right-of-use assets Depreciation and amortization 1,117 1,494 3,546 4,224 Interest on lease liability Interest expense and other 410 387 1,162 1,579 Total lease cost (1) $ 8,322 $ 9,120 $ 29,844 $ 29,524 (1) Total lease cost does not include short-term leases or sublease income, both of which are immaterial.
Schedule of Supplemental Cash Flow Information	Supplemental cash flow information for the nine months ended December 31, 2020 and 2019, is disclosed in the table below. Nine Months Ended December 31, 2020 2019 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows used in operating leases $ 13,056 $ 14,046 Operating cash flows used in finance leases 1,164 1,600 Financing cash flows used in finance leases 6,170 6,516 ROU assets obtained in exchange for lease liabilities Operating leases 5,506 2,569 Finance leases 538 811
Schedule of Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases as of December 31, 2020 and March 31, 2020, is disclosed in the table below. Leases Classification December 31, 2020 March 31, 2020 Assets Operating lease ROU assets Other, net Assets held for sale $ 50,434 $ 61,461 Finance lease ROU assets, cost Property and equipment, net Assets held for sale 41,757 39,461 Accumulated amortization Property and equipment, net Assets held for sale (22,217 ) (18,650 ) Finance lease ROU assets, net 19,540 20,811 Total lease assets $ 69,974 $ 82,272 Liabilities Current Operating Accrued expenses Liabilities related to assets held for sale $ 16,249 $ 13,139 Finance Current portion of long-term debt Liabilities related to assets held for sale 6,093 7,336 Noncurrent Operating Other noncurrent liabilities Liabilities related to assets held for sale 46,313 54,687 Finance Long-term debt, less current portion Liabilities related to assets held for sale 14,048 16,597 Total lease liabilities $ 82,703 $ 91,759
Schedule of Information Related to Lease Terms and Discount Rates	Information related to lease terms and discount rates as of December 31, 2020 and March 31, 2020, is disclosed in the table below. December 31, 2020 March 31, 2020 Weighted average remaining lease term (years) Operating leases 7.0 7.2 Finance leases 7.0 6.9 Weighted average discount rate Operating leases 6.3 % 6.2 % Finance leases 6.4 % 5.9 %
Schedule of Maturity of Lease Liabilities	The maturity of the Company's lease liabilities as of December 31, 2020, is disclosed in the table below. Operating leases Finance leases Total FY2021 (remaining of year) $ 7,074 $ 2,106 $ 9,180 FY2022 15,766 6,367 22,133 FY2023 10,602 3,413 14,015 FY2024 7,601 2,734 10,335 FY2025 6,909 1,361 8,270 Thereafter 31,115 9,959 41,074 Total lease payments 79,067 25,940 105,007 Less: Imputed interest (16,505 ) (5,799 ) (22,304 ) Total lease liabilities $ 62,562 $ 20,141 $ 82,703

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Components of Inventories	Inventories are stated at the lower of cost (average-cost or specific-identification methods) or market. The components of inventories are as follows: December 31, 2020 March 31, 2020 Raw materials $ 53,250 $ 32,552 Work-in-process, including manufactured and purchased components 306,589 312,953 Finished goods 55,628 50,011 Rotable assets 30,741 57,460 Total inventories $ 446,208 $ 452,976

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	Long-term debt consists of the following: December 31, 2020 March 31, 2020 Revolving credit facility $ — $ 400,000 Receivable securitization facility — 75,000 Finance leases 20,137 23,933 Senior secured first lien notes due 2024 700,000 — Senior secured notes due 2024 525,000 525,000 Senior notes due 2022 300,000 300,000 Senior notes due 2025 500,000 500,000 Less: debt issuance costs (25,792 ) (16,426 ) 2,019,345 1,807,507 Less: current portion 6,090 7,336 $ 2,013,255 $ 1,800,171
Schedule of Carrying Amounts and Estimated Fair Values of Long-term Debt	Carrying amounts and the related estimated fair values of the Company's long-term debt not recorded at fair value in the consolidated financial statements are as follows: December 31, 2020 March 31, 2020 Carrying Value Fair Value Carrying Value Fair Value $ 2,019,345 $ 2,053,717 $ 1,807,507 $ 1,559,455

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Summary of Reconciliation between Weighted-average Common Shares Outstanding used in Calculation of Basis and Diluted Earnings Per Share	The following is a reconciliation between the weighted average outstanding shares used in the calculation of basic and diluted earnings per share: Three Months Ended December 31, Nine Months Ended December 31, (in thousands) (in thousands) 2020 2019 2020 2019 Weighted average common shares outstanding – basic 52,488 50,395 52,126 50,074 Net effect of dilutive stock options and non-vested stock (1) — — — 517 Weighted average common shares outstanding – diluted 52,488 50,395 52,126 50,591 (1) For the three and nine months ended December 31, 2020 and 2019, the shares that could potentially dilute earnings per share in the future but were not included in diluted weighted average common shares outstanding because to do so would have been anti-dilutive were immaterial.

Pension and Other Postretirem_2

Pension and Other Postretirement Benefit Plans (Tables)	9 Months Ended
	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Schedule of Components of Net Periodic Benefit Cost (Income)	The components of net periodic benefit costs (income) for our postretirement benefit plans are shown in the following table: Pension Benefits Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 (1) 2020 2019 (1) Components of net periodic benefit costs: Service cost $ 386 $ 577 $ 1,146 $ 1,758 Interest cost 16,107 16,073 48,294 52,162 Expected return on plan assets (34,154 ) (35,900 ) (102,395 ) (106,518 ) Amortization of prior service credits 243 (183 ) 728 (695 ) Amortization of net loss 7,812 7,632 23,417 20,651 Curtailment loss — — — 23,476 Special termination benefits — — — 11,642 Net periodic benefit income $ (9,606 ) $ (11,801 ) $ (28,810 ) $ 2,476 (1) As adjusted; refer to Note 1. Other Postretirement Benefits Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 Components of net periodic benefit costs: Service cost $ — $ — $ — $ 62 Interest cost 28 41 84 1,519 Amortization of prior service credits (1,276 ) (1,276 ) (3,828 ) (3,596 ) Amortization of gain (1,191 ) (1,186 ) (3,574 ) (5,175 ) Curtailment gain — — — (49,491 ) Net periodic benefit income $ (2,439 ) $ (2,421 ) $ (7,318 ) $ (56,681 ) (1) As adjusted; refer to Note 1.

Stockholders' Deficit (Tables)

Stockholders' Deficit (Tables)	9 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Loss	Changes in accumulated other comprehensive loss ("AOCI") by component for the three and nine months ended December 31, 2020 and 2019, were as follows: Currency Translation Adjustment Unrealized Gains and Losses on Derivative Instruments Defined Benefit Pension Plans and Other Postretirement Benefits Total (2) September 30, 2020 $ (53,844 ) $ 28 $ (671,570 ) $ (725,386 ) AOCI before reclassifications 12,637 1,878 — 14,515 Amounts reclassified from AOCI — 437 4,265 (3) 4,702 Net current period OCI 12,637 2,315 4,265 19,217 December 31, 2020 $ (41,207 ) $ 2,343 $ (667,305 ) $ (706,169 ) September 30, 2019 (1) $ (57,516 ) $ (2,527 ) $ (532,554 ) $ (592,597 ) AOCI before reclassifications 11,074 4,581 — 15,655 Amounts reclassified from AOCI — (80 ) 4,387 (3) 4,307 Net current period OCI 11,074 4,501 4,387 19,962 December 31, 2019 (1) $ (46,442 ) $ 1,974 $ (528,167 ) $ (572,635 ) March 31, 2020 (1) $ (62,045 ) $ (4,303 ) $ (680,100 ) $ (746,448 ) AOCI before reclassifications 20,838 8,308 — 29,146 Amounts reclassified from AOCI — (1,662 ) 12,795 (3) 11,133 Net current period OCI 20,838 6,646 12,795 40,279 December 31, 2020 $ (41,207 ) $ 2,343 $ (667,305 ) $ (706,169 ) March 31, 2019 (1) $ (48,606 ) $ (1,130 ) $ (466,275 ) $ (516,011 ) AOCI before reclassifications 2,164 4,921 (122,971 ) (115,886 ) Amounts reclassified from AOCI — (1,817 ) 61,079 (3) 59,262 Net current period OCI 2,164 3,104 (61,892 ) (56,624 ) December 31, 2019 (1) $ (46,442 ) $ 1,974 $ (528,167 ) $ (572,635 ) (1) As adjusted; refer to Note 1. (2) Net of tax. (3) Includes amortization of actuarial losses and recognized prior service (credits) costs, which are included in net periodic pension cost of which a portion is allocated to production as inventoried costs. Net periodic pension cost is presented in cost of sales and non-service defined benefit income on the accompanying condensed consolidated statements of operations. Refer to Note 11 for additional disclosure regarding our postretiremend benefit plans.

Segments (Tables)

Segments (Tables)	9 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Schedule of Selected Financial Information for Each Reportable Segment and Reconciliation of EBITDAP to Operating Income	Selected financial information for each reportable segment is as follows: Three Months Ended December 31, 2020 Total Corporate & Eliminations Systems & Support Aerospace Structures Net sales to external customers $ 425,994 $ — $ 263,638 $ 162,356 Intersegment sales (eliminated in consolidation) — (536 ) 482 54 Segment profit and reconciliation to consolidated income before income taxes: Adjusted EBITDAP 61,407 — 46,746 14,661 Reconciliation of segment profit to income (loss) before income taxes Depreciation and amortization (22,119 ) (989 ) (8,353 ) (12,777 ) Interest expense and other, net (44,881 ) Corporate expenses (8,483 ) Share-based compensation expense (3,679 ) Loss on sale of assets and businesses (45,273 ) Amortization of acquired contract liabilities 6,867 Non-service defined benefit income 12,432 Impairment of rotable inventory (23,689 ) Loss before income taxes (67,418 ) Total capital expenditures $ 6,184 $ 158 $ 2,308 $ 3,718 Total assets $ 2,401,922 $ 451,824 $ 1,463,017 $ 487,081 Three Months Ended December 31, 2019 (1) Total Corporate & Eliminations Systems & Support Aerospace Structures Net sales to external customers $ 704,666 $ — $ 337,207 $ 367,459 Intersegment sales (eliminated in consolidation) — (3,230 ) 1,717 1,513 Segment profit and reconciliation to consolidated income before income taxes: Adjusted EBITDAP 89,272 — 57,132 32,140 Reconciliation of segment profit to income (loss) before income taxes Depreciation and amortization (29,843 ) (847 ) (8,075 ) (20,921 ) Interest expense and other, net (33,178 ) Corporate expenses (13,848 ) Share-based compensation expense (2,955 ) Loss on sale of assets and businesses (60,019 ) Amortization of acquired contract liabilities 16,597 Non-service defined benefit income 14,799 Union represented employee incentives (1,400 ) Legal judgment gain, net 3,857 Loss before income taxes (16,718 ) Total capital expenditures $ 10,255 $ 416 $ 3,929 $ 5,910 Nine Months Ended December 31, 2020 Total Corporate & Eliminations Systems & Support Aerospace Structures Net sales to external customers $ 1,402,886 $ — $ 755,290 $ 647,596 Intersegment sales (eliminated in consolidation) — (4,357 ) 2,888 1,469 Segment profit and reconciliation to consolidated income before income taxes: Adjusted EBITDAP 131,067 — 110,983 20,084 Reconciliation of segment profit to income (loss) before income taxes Depreciation and amortization (72,819 ) (2,652 ) (24,830 ) (45,337 ) Interest expense and other, net (132,344 ) Corporate expenses (42,027 ) Share-based compensation expense (9,086 ) Loss on sale of assets and businesses (46,020 ) Amortization of acquired contract liabilities 35,017 Non-service defined benefit income 37,275 Impairment of rotable inventory (23,689 ) Impairment of long-lived assets (252,382 ) Loss before income taxes (375,008 ) Total capital expenditures $ 18,988 $ 801 $ 11,819 $ 6,368 Nine Months Ended December 31, 2019 (1) Total Corporate & Eliminations Systems & Support Aerospace Structures Net sales to external customers $ 2,207,007 $ — $ 1,001,384 $ 1,205,623 Intersegment sales (eliminated in consolidation) — (9,224 ) 4,118 5,106 Segment profit and reconciliation to consolidated income before income taxes: Adjusted EBITDAP 250,126 — 162,008 88,118 Reconciliation of segment profit to income (loss) before income taxes Depreciation and amortization (104,112 ) (2,533 ) (24,314 ) (77,265 ) Interest expense and other, net (96,069 ) Corporate expenses (42,709 ) Share-based compensation expense (8,245 ) Loss on sale of assets and businesses (55,190 ) Amortization of acquired contract liabilities 56,153 Non-service defined benefit income 56,025 Union represented employee incentives (7,071 ) Legal judgment gain, net 9,257 Income before income taxes 58,165 Total capital expenditures $ 27,250 $ 980 $ 12,355 $ 13,915 (1) As adjusted; refer to Note 1.

Background and Basis of Prese_3

Background and Basis of Presentation - Additional Information (Details)	9 Months Ended
	Dec. 31, 2020Segment
Background And Basis Of Presentation [Line Items]
Number of reportable segments	2
Defined benefit plan percentage of fair value of investments of other pension assets	56.00%
Amortization period of gains and losses on other plan assets to be amortized into earnings	5 years
Change in Accounting Principle [Member]
Background And Basis Of Presentation [Line Items]
Defined benefit plan percentage of fair value of investments of fixed income assets	44.00%
ASU 2016-13 [Member]
Background And Basis Of Presentation [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Apr. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
ASU 2018-13 [Member]
Background And Basis Of Presentation [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Apr. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true

Background and Basis of Prese_4

Background and Basis of Presentation -Schedule of Impact of Change in Accounting Principle on Condensed Consolidated Statement of Operations and Condensed Consolidated Statements of Comprehensive Loss (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Non-service defined benefit income	$ (12,432)	$ (14,799)	[1]	$ (37,275)	$ (56,025)	[1]
(Loss) income before income taxes	(67,418)	(16,718)	[1]	(375,008)	58,165	[1]
Income tax expense (benefit)	698	(3,512)	[1]	2,383	12,213	[1]
Net (loss) income	$ (68,116)	$ (13,206)	[1]	$ (377,391)	$ 45,952	[1]
Net (Loss) Income per share - basic & diluted
Basic	$ (1.30)	$ (0.26)	[1]	$ (7.24)	$ 0.92	[1]
Diluted	$ (1.30)	$ (0.26)	[1]	$ (7.24)	$ 0.91	[1]
Defined benefit pension plans and other postretirement benefits (expense):
Total defined benefit pension plans and other postretirement benefits (expense), net of taxes	$ 4,265	$ 4,387	[1]	$ 12,795	$ (61,892)	[1]
Total other comprehensive income (loss)	19,217	19,962	[1]	40,279	(56,624)	[1]
Comprehensive income (loss)	(48,899)	6,756	[1]	(337,112)	(10,672)	[1]
Previously Reported [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Non-service defined benefit income	(13,960)	(13,989)		(41,859)	(57,280)
(Loss) income before income taxes	(65,890)	(17,528)		(370,424)	59,420
Income tax expense (benefit)	698	(3,682)		2,383	12,477
Net (loss) income	$ (66,588)	$ (13,846)		$ (372,807)	$ 46,943
Net (Loss) Income per share - basic & diluted
Basic	$ (1.27)	$ (0.27)		$ (7.15)	$ 0.94
Diluted	$ (1.27)	$ (0.27)		$ (7.15)	$ 0.93
Defined benefit pension plans and other postretirement benefits (expense):
Total defined benefit pension plans and other postretirement benefits (expense), net of taxes	$ 2,737	$ 5,027		$ 8,211	$ (62,883)
Total other comprehensive income (loss)	17,689	20,602		35,695	(57,615)
Comprehensive income (loss)	(48,899)	6,756		(337,112)	(10,672)
Impact of Change [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Non-service defined benefit income	(1,528)	(810)		(4,584)	1,255
(Loss) income before income taxes	1,528	810		4,584	(1,255)
Income tax expense (benefit)		170			(264)
Net (loss) income	$ 1,528	$ 640		$ 4,584	$ (991)
Net (Loss) Income per share - basic & diluted
Basic	$ 0.03	$ 0.01		$ 0.09	$ (0.02)
Diluted	$ 0.03	$ 0.01		$ 0.09	$ (0.02)
Defined benefit pension plans and other postretirement benefits (expense):
Total defined benefit pension plans and other postretirement benefits (expense), net of taxes	$ (1,528)	$ (640)		$ (4,584)	$ 991
Total other comprehensive income (loss)	$ (1,528)	$ (640)		$ (4,584)	$ 991
[1]	As adjusted; refer to Note 1.

Background and Basis of Prese_5

Background and Basis of Presentation -Schedule of Impact of Change in Accounting Principle on Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020	[1]	Jun. 30, 2020	[1]	Mar. 31, 2020		Dec. 31, 2019	[1]	Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2019	[1]
Stockholders' deficit:
Accumulated other comprehensive loss	$ (706,169)					$ (746,448)	[1]
Accumulated deficit	(1,180,872)					(803,481)	[1]
Total stockholders' deficit	(1,069,830)	$ (1,064,357)		$ (1,047,381)		(781,264)	[1]	$ (532,897)		$ (590,824)		$ (557,919)		$ (573,313)
Previously Reported [Member]
Stockholders' deficit:
Accumulated other comprehensive loss	(737,773)					(719,428)
Accumulated deficit	(1,149,268)					(830,501)
Total stockholders' deficit	(1,069,830)					(781,264)
Impact of Change [Member]
Stockholders' deficit:
Accumulated other comprehensive loss	(31,604)					(27,020)
Accumulated deficit	$ 31,604					$ 27,020
[1]	As adjusted; refer to Note 1.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	3 Months Ended			9 Months Ended			12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2020	Dec. 31, 2019		Mar. 31, 2020
Change In Accounting Estimate [Line Items]
Net sales	$ 425,994,000	$ 704,666,000	[1]	$ 1,402,886,000	$ 2,207,007,000	[1]
Income taxes paid, net of refunds received				$ 2,474,000	$ 4,370,000
Trade Accounts Receivable [Member] | Credit Concentration Risk [Member]
Change In Accounting Estimate [Line Items]
Concentration Risk, Percentage				10.00%
Revenue from Contract with Customer [Member] | Credit Concentration Risk [Member]
Change In Accounting Estimate [Line Items]
Concentration Risk, Percentage				10.00%
Boeing [Member] | Trade Accounts Receivable [Member] | Credit Concentration Risk [Member]
Change In Accounting Estimate [Line Items]
Concentration Risk, Percentage				19.00%			21.00%
Boeing [Member] | Net sales [Member] | Credit Concentration Risk [Member]
Change In Accounting Estimate [Line Items]
Concentration Risk, Percentage				38.00%	34.00%
Net sales				$ 528,263,000	$ 742,495,000
Boeing [Member] | Net sales [Member] | Credit Concentration Risk [Member] | Systems & Support [Member]
Change In Accounting Estimate [Line Items]
Net sales				164,520,000	189,854,000
Boeing [Member] | Net sales [Member] | Credit Concentration Risk [Member] | Aerospace Structures [Member]
Change In Accounting Estimate [Line Items]
Net sales				$ 363,743,000	$ 552,641,000
Bombardier [Member] | Trade Accounts Receivable [Member] | Credit Concentration Risk [Member]
Change In Accounting Estimate [Line Items]
Concentration Risk, Percentage				2.00%			16.00%
Gulfstream [Member] | Net sales [Member] | Credit Concentration Risk [Member]
Change In Accounting Estimate [Line Items]
Concentration Risk, Percentage				7.00%	12.00%
Net sales				$ 100,364,000	$ 268,917,000
Gulfstream [Member] | Net sales [Member] | Credit Concentration Risk [Member] | Systems & Support [Member]
Change In Accounting Estimate [Line Items]
Net sales				2,166,000	2,497,000
Gulfstream [Member] | Net sales [Member] | Credit Concentration Risk [Member] | Aerospace Structures [Member]
Change In Accounting Estimate [Line Items]
Net sales				98,197,000	266,421,000
Revenue Benchmark [Member]
Change In Accounting Estimate [Line Items]
Change in accounting estimate	(37,000)	4,722,000		4,577,000	2,347,000
Operating Income (Loss) [Member]
Change In Accounting Estimate [Line Items]
Change in accounting estimate	3,688,000	(210,000)		19,349,000	(16,393,000)
Income (Loss), Net [Member]
Change In Accounting Estimate [Line Items]
Change in accounting estimate	3,688,000	(166,000)		19,349,000	(12,950,000)
Earnings (Loss) Per Share [Member]
Change In Accounting Estimate [Line Items]
Change in accounting estimate	$ 0.07	$ 0		$ 0.37	$ (0.26)
Minimum [Member]
Change In Accounting Estimate [Line Items]
Standard trade receivable, payment terms				30 days
Maximum [Member]
Change In Accounting Estimate [Line Items]
Standard trade receivable, payment terms				120 days
[1]	As adjusted; refer to Note 1.

Divested Operations and Asset_2

Divested Operations and Assets Held For Sale - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended				3 Months Ended			9 Months Ended
	Aug. 31, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2020	Dec. 31, 2019
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Impairment on the assets held for sale					$ 45,201
Proceeds from divestiture of businesses			$ 58,000
Gain (loss) on disposition of assets				$ 10,000	$ (45,273)	$ (60,019)	[1]	$ (46,020)	$ (55,190)	[1]
Guarantor obligations, current carrying value			7,000			7,000			7,000
Gain (loss) on disposition of property plant equipment			(64,000)
Defined benefit plan, plan assets, amount			$ 55,000			$ 55,000			$ 55,000
Defined benefit plan, net periodic benefit cost (credit), gain (loss) due to settlement and curtailment		$ (28,000)
Gulfstream G650 [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from divestiture of businesses	$ 52,000
Gain (loss) on disposition of assets	$ 747
[1]	As adjusted; refer to Note 1.

Revenue Recognition and Contr_3

Revenue Recognition and Contracts with Customers - Schedule of Disaggregated Net Sales Satisfied Overtime and at a Point in Time (Excluding Intercompany Sales) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Amortization of acquired contract liabilities	$ 6,867	$ 16,597		$ 35,017	$ 56,153
Net sales	425,994	704,666	[1]	1,402,886	2,207,007	[1]
Systems & Support [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	259,332	328,830		743,721	975,258
Amortization of acquired contract liabilities	4,306	8,377		11,569	26,126
Revenues excluding intercompany sales	263,638	337,207		755,290	1,001,384
Systems & Support [Member] | Transferred over Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	118,813	135,229		324,968	403,825
Systems & Support [Member] | Transferred at Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	140,519	193,601		418,753	571,433
Aerospace Structures [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	159,795	359,239		624,148	1,175,596
Amortization of acquired contract liabilities	2,561	8,220		23,448	30,027
Revenues excluding intercompany sales	162,356	367,459		647,596	1,205,623
Aerospace Structures [Member] | Transferred over Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	148,526	330,657		596,145	1,075,141
Aerospace Structures [Member] | Transferred at Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	$ 11,269	$ 28,582		$ 28,003	$ 100,455
[1]	As adjusted; refer to Note 1.

Revenue Recognition and Contr_4

Revenue Recognition and Contracts with Customers - Schedule of Disaggregated Net Sales by End Market (Excluding Intercompany Sales) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Amortization of acquired contract liabilities	$ 6,867	$ 16,597		$ 35,017	$ 56,153
Net sales	425,994	704,666	[1]	1,402,886	2,207,007	[1]
Systems & Support [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	259,332	328,830		743,721	975,258
Amortization of acquired contract liabilities	4,306	8,377		11,569	26,126
Revenues excluding intercompany sales	263,638	337,207		755,290	1,001,384
Systems & Support [Member] | Commercial Aerospace [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	92,529	192,232		280,102	561,815
Systems & Support [Member] | Military [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	145,168	105,860		396,672	309,735
Systems & Support [Member] | Business Jets [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	7,802	10,776		26,884	45,280
Systems & Support [Member] | Regional [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	5,231	11,310		18,218	33,434
Systems & Support [Member] | Non-aviation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	8,602	8,652		21,845	24,994
Aerospace Structures [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	159,795	359,239		624,148	1,175,596
Amortization of acquired contract liabilities	2,561	8,220		23,448	30,027
Revenues excluding intercompany sales	162,356	367,459		647,596	1,205,623
Aerospace Structures [Member] | Commercial Aerospace [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	109,929	208,943		372,249	681,471
Aerospace Structures [Member] | Military [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	31,670	27,394		105,365	83,773
Aerospace Structures [Member] | Business Jets [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	18,039	98,370		138,141	330,178
Aerospace Structures [Member] | Regional [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers		24,523		8,025	80,155
Aerospace Structures [Member] | Non-aviation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	$ 157	$ 9		$ 368	$ 19
[1]	As adjusted; refer to Note 1.

Revenue Recognition and Contr_5

Revenue Recognition and Contracts with Customers - Summary of Contract Assets and Liabilities Balances (Details) - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2020	Mar. 31, 2020
Revenue From Contract With Customer [Abstract]
Contract assets	$ 175,099	$ 267,079
Contract liabilities	(278,690)	(386,585)
Net contract liability	(103,591)	$ (119,506)
Change in contract assets	(91,980)
Change in contract liabilities	107,895
Change in net contract liability	$ 15,915

Revenue Recognition and Contr_6

Revenue Recognition and Contracts with Customers - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2020
Contract With Customer Asset And Liability [Line Items]
Change in contract assets			$ 91,980
Contract with customer, contract assets classified as held for sale	$ 33,568		33,568
Contract with customer, contract liability classified as held for sale	13,670		13,670
Contract with Customer, Liability, Revenue Recognized			71,433
Contract with Customer, Asset, Net, Noncurrent	16,810		16,810		$ 22,662
Contract with Customer, Liability, Noncurrent	110,918		110,918		$ 91,265
Gulfstream G650 [Member]
Contract With Customer Asset And Liability [Line Items]
Change in contract assets			60,802
Revenue Benchmark [Member]
Contract With Customer Asset And Liability [Line Items]
Revenue recognized due to changes in estimates associated with performance obligations	$ (37)	$ 4,722	$ 4,577	$ 2,347

Revenue Recognition and Contr_7

Revenue Recognition and Contracts with Customers - Schedule of Performance Obligations that are Expected to Be Recognized in Future (Details) $ in Thousands	Dec. 31, 2020USD ($)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Unsatisfied performance obligations	$ 2,465,352
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Unsatisfied performance obligations	1,330,301
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Unsatisfied performance obligations	1,063,968
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Unsatisfied performance obligations	71,055
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2026-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Unsatisfied performance obligations	$ 28
Maximum [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Maximum [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	3 years
Maximum [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	5 years
Minimum [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Minimum [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	4 years
Minimum [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2026-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	5 years

Revenue Recognition and Contr_8

Revenue Recognition and Contracts with Customers - Schedule of Performance Obligations that are Expected to Be Recognized in Future (Details 1) $ in Thousands	Dec. 31, 2020USD ($)
Revenue From Contract With Customer [Abstract]
Unsatisfied performance obligations	$ 2,465,352

Leases - Schedule of Components

Leases - Schedule of Components Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Lessee Lease Description [Line Items]
Total lease cost	$ 8,322	$ 9,120	$ 29,844	$ 29,524
Cost of sales or Selling, general and administrative expense [Member]
Lessee Lease Description [Line Items]
Operating lease cost	4,343	5,069	17,980	17,829
Variable lease cost	2,452	2,170	7,156	5,892
Depreciation and amortization [Member]
Lessee Lease Description [Line Items]
Amortization of right-of-use assets	1,117	1,494	3,546	4,224
Interest expense and other [Member]
Lessee Lease Description [Line Items]
Interest on lease liability	$ 410	$ 387	$ 1,162	$ 1,579

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows used in operating leases	$ 13,056	$ 14,046
Operating cash flows used in finance leases	1,164	1,600
Financing cash flows used in finance leases	6,170	6,516
ROU assets obtained in exchange for lease liabilities
Operating leases	5,506	2,569
Finance leases	$ 538	$ 811

Leases - Schedule of Suppleme_2

Leases - Schedule of Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
ASSETS
Operating lease ROU assets	$ 50,434	$ 61,461
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:AssetsHeldForSaleNotPartOfDisposalGroupCurrent	us-gaap:OtherAssetsNoncurrent
Finance lease ROU assets, cost	$ 41,757	$ 39,461
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:AssetsHeldForSaleNotPartOfDisposalGroupCurrent	us-gaap:PropertyPlantAndEquipmentNet
Accumulated amortization	$ (22,217)	$ (18,650)
Finance Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:AssetsHeldForSaleNotPartOfDisposalGroupCurrent	us-gaap:PropertyPlantAndEquipmentMember
Finance lease ROU assets, net	$ 19,540	$ 20,811
Total lease assets	69,974	82,272
Current liabilities:
Operating	$ 16,249	$ 13,139
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	tgi:LiabilitiesRelatedToAssetsHeldForSaleCurrent	us-gaap:AccruedLiabilitiesCurrent
Finance	$ 6,093	$ 7,336
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	tgi:LiabilitiesRelatedToAssetsHeldForSaleCurrent	us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent
Noncurrent
Operating	$ 46,313	$ 54,687
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	tgi:LiabilitiesRelatedToAssetsHeldForSaleCurrent	us-gaap:OtherLiabilitiesNoncurrent
Finance	$ 14,048	$ 16,597
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	tgi:LiabilitiesRelatedToAssetsHeldForSaleCurrent	us-gaap:LongTermDebtAndCapitalLeaseObligations
Total lease liabilities	$ 82,703	$ 91,759

Leases - Schedule of Informatio

Leases - Schedule of Information Related to Lease Terms and Discount Rates (Details)	Dec. 31, 2020	Mar. 31, 2020
Leases [Abstract]
Operating leases	7 years	7 years 2 months 12 days
Finance leases	7 years	6 years 10 months 24 days
Operating leases	6.30%	6.20%
Finance leases	6.40%	5.90%

Leases - Schedule of Maturity o

Leases - Schedule of Maturity of Lease Liabilities (Details) $ in Thousands	Dec. 31, 2020USD ($)
Leases [Abstract]
Operating leases, FY2021 (remaining of year)	$ 7,074
Operating leases, FY2022	15,766
Operating leases, FY2023	10,602
Operating leases, FY2024	7,601
Operating leases, FY2025	6,909
Operating leases, Thereafter	31,115
Total operating lease payments	79,067
Operating leases, Less: Imputed interest	(16,505)
Total operating lease liabilities	62,562
Finance leases, FY2021 (remaining of year)	2,106
Finance leases, FY2022	6,367
Finance leases, FY2023	3,413
Finance leases, FY2024	2,734
Finance leases, FY2025	1,361
Finance leases, Thereafter	9,959
Total finance lease payments	25,940
Finance leases, Less: Imputed interest	(5,799)
Total finance lease liabilities	20,141
Total lease payment, FY2021 (remaining of year)	9,180
Total lease payment, FY2022	22,133
Total lease payment, FY2023	14,015
Total lease payment, FY2024	10,335
Total lease payment, FY2025	8,270
Total lease payments, Thereafter	41,074
Total lease payments	105,007
Total lease payment, Less: Imputed interest	(22,304)
Total lease liabilities	$ 82,703

Inventories - Schedule of Compo

Inventories - Schedule of Components of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
Inventory Disclosure [Abstract]
Raw materials	$ 53,250	$ 32,552
Work-in-process	306,589	312,953
Finished goods	55,628	50,011
Rotable assets	30,741	57,460
Total inventories	$ 446,208	$ 452,976	[1]
[1]	As adjusted; refer to Note 1.

Inventories - Additional Inform

Inventories - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Dec. 31, 2020	Dec. 31, 2020
Inventory Disclosure [Abstract]
Impairment loss on rotable inventory	$ 23,689	$ 23,689

Long-term Debt - Schedule of Lo

Long-term Debt - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
Debt Instrument [Line Items]
Less: debt issuance costs	$ (25,792)	$ (16,426)
Long-term debt	2,019,345	1,807,507
Current portion of long-term debt	6,090	7,336	[1]
Long-term debt, less current portion	2,013,255	1,800,171	[1]
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term debt		400,000
Receivable Securitization Facility [Member]
Debt Instrument [Line Items]
Long-term debt	0	75,000
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Long-term debt	20,137	23,933
Senior Secured First Lien Notes Due 2024 [Member]
Debt Instrument [Line Items]
Long-term debt	700,000
Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Long-term debt	525,000	525,000
Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Long-term debt	300,000	300,000
Senior Notes Due 2025 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 500,000	$ 500,000
[1]	As adjusted; refer to Note 1.

Long-term Debt - Additional Inf

Long-term Debt - Additional Information (Details) - USD ($)	Aug. 17, 2020	Oct. 23, 2019	Sep. 23, 2019	Aug. 17, 2017	Jun. 03, 2014	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2020
Debt Instrument [Line Items]
Payments of financing costs						$ 20,215,000	$ 17,545,000
Interest paid, including capitalized interest, operating and investing activities						79,382,000	$ 60,885,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Payment of line of credit facility	$ 335,240,000
Long-term debt								$ 400,000,000
Receivable Securitization Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity						75,000,000
Long-term debt						0		75,000,000
Letters of credit outstanding, amount						$ 27,779,000
Receivables securitization facility, expiration period						2022-12
Receivable Securitization Facility [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage	2.50%
Line of credit facility, unused capacity, commitment fee percentage	0.60%
Receivable Securitization Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity						$ 50,000,000
Receivable Securitization Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	0.75%
Senior Secured First Lien Notes Due 2024 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	8.875%
Long-term debt						$ 700,000,000
Debt instrument, principal amount	$ 700,000,000
Proceeds from loan, percentage of principal (as a percent)	100.00%
Debt instrument, interest rate, effective percentage	8.875%
Debt instrument, interest payment terms						Interest is payable semi-annually in cash in arrears on June 1 and December 1 of each year, commencing on December 1, 2020
Debt instrument, interest payment commencing date	Dec. 1, 2020
Payments of financing costs	$ 13,000,000
Debt instrument, redemption price, percentage	100.00%
Debt instrument, redemption, description	40.00%
Debt instrument, redemption price, percentage - equity offering	108.875%
Debt instrument, redemption price, percentage - change of control	101.00%
Debt instrument repayment premium percentage	106.656%
Aggregate principal amount of Notes outstanding	$ 350,000,000
Available amount in asset sale covenants	$ 100,000,000
Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			6.25%
Long-term debt						$ 525,000,000		525,000,000
Debt instrument, principal amount			$ 525,000,000
Proceeds from loan, percentage of principal (as a percent)			100.00%
Debt instrument, interest rate, effective percentage			6.25%
Debt instrument, interest payment terms						Interest on the 2024 Notes is payable semiannually in cash in arrears on March 15 and September 15 of each year. The 2024 Notes are secured by second-priority liens on all of the Company's and the Guarantor Subsidiaries' assets that secure all of the indebtedness under the Credit Facility and certain hedging and cash management obligations.
Debt instrument, due date			Sep. 15, 2024
Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		4.875%
Debt instrument principal amount redeemed		$ 375,000,000
Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage					5.25%
Long-term debt						$ 300,000,000		300,000,000
Debt instrument, principal amount					$ 300,000,000
Proceeds from loan, percentage of principal (as a percent)					100.00%
Debt instrument, interest rate, effective percentage					5.25%
Debt instrument, interest payment terms						Interest on the 2022 Notes accrues at the rate of 5.250% per annum and is payable semiannually in cash in arrears on June 1 and December 1 of each year.
Debt instrument, due date					Jun. 1, 2022
Senior Notes Due 2025 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.75%
Long-term debt						$ 500,000,000		$ 500,000,000
Debt instrument, principal amount				$ 500,000,000
Proceeds from loan, percentage of principal (as a percent)				100.00%
Debt instrument, interest payment terms						Interest on the 2025 Notes accrues at the rate of 7.750% per annum and is payable semiannually in cash in arrears on February 15 and August 15 of each year.
Debt instrument, due date				Aug. 15, 2025

Long-term Debt - Schedule of Ca

Long-term Debt - Schedule of Carrying Amounts and Estimated Fair Values of Long-term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
Debt Instrument [Line Items]
Long-term debt	$ 2,019,345	$ 1,807,507
Reported Value Measurement [Member]
Debt Instrument [Line Items]
Long-term debt	2,019,345	1,807,507
Estimate of Fair Value Measurement [Member]
Debt Instrument [Line Items]
Long-term debt	$ 2,053,717	$ 1,559,455

Earnings per Share - Summary of

Earnings per Share - Summary of Reconciliation between Weighted-average Common Shares Outstanding used in Calculation of Basis and Diluted Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended			9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	[1]	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Weighted average common shares outstanding—basic	52,488	50,395		52,126	50,074	[1]
Net effect of dilutive stock options and non-vested stock					517
Weighted average common shares outstanding – diluted	52,488	50,395		52,126	50,591	[1]
[1]	As adjusted; refer to Note 1.

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 18,908		$ 18,908		$ 18,965
Effective income tax rate (as a percent)	(1.00%)	21.00%	(0.60%)	21.00%

Long-Lived Assets - Additional

Long-Lived Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Jun. 30, 2020	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Discount rate used to estimate fair value of asset group		15.00%
Noncash impairment charge	$ 252,382	$ 252,382

Pension and Other Postretirem_3

Pension and Other Postretirement Benefit Plans - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Dec. 31, 2020	Mar. 31, 2022
Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated cash contributions		$ 58,000
Reduction in estimated cash contributions		$ 18,000
Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of Shares contributed	2,849,002
Aggregate value of Shares contributed	$ 40,000

Pension and Other Postretirem_4

Pension and Other Postretirement Benefit Plans - Schedule of Components of Net Periodic Benefit Cost (Income) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Curtailment (gain) loss	$ 28,000
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 386	$ 577	$ 1,146	$ 1,758
Interest cost		16,107	16,073	48,294	52,162
Expected return on plan assets		(34,154)	(35,900)	(102,395)	(106,518)
Amortization of prior service credits		243	(183)	728	(695)
Amortization of net (gain) loss		7,812	7,632	23,417	20,651
Curtailment (gain) loss					23,476
Special termination benefits					11,642
Net periodic benefit income		(9,606)	(11,801)	(28,810)	2,476
Other postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost					62
Interest cost		28	41	84	1,519
Amortization of prior service credits		(1,276)	(1,276)	(3,828)	(3,596)
Amortization of net (gain) loss		(1,191)	(1,186)	(3,574)	(5,175)
Curtailment (gain) loss					(49,491)
Net periodic benefit income		$ (2,439)	$ (2,421)	$ (7,318)	$ (56,681)

Stockholders' Deficit - Schedul

Stockholders' Deficit - Schedule of Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2020	Dec. 31, 2019
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Balance	[1]	$ (1,064,357)	$ (590,824)		$ (781,264)	$ (573,313)
Total other comprehensive income (loss)		19,217	19,962	[1]	40,279	(56,624)	[1]
Balance		(1,069,830)	(532,897)	[1]	(1,069,830)	(532,897)	[1]
Currency Translation Adjustment [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Balance		(53,844)	(57,516)		(62,045)	(48,606)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax		12,637	11,074		20,838	2,164
Total other comprehensive income (loss)		12,637	11,074		20,838	2,164
Balance		(41,207)	(46,442)		(41,207)	(46,442)
Unrealized Gains and Losses on Derivative Instruments [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Balance		28	(2,527)		(4,303)	(1,130)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax		1,878	4,581		8,308	4,921
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax		437	(80)		(1,662)	(1,817)
Total other comprehensive income (loss)		2,315	4,501		6,646	3,104
Balance		2,343	1,974		2,343	1,974
Defined Benefit Pension Plans and Other Postretirement Benefits [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Balance		(671,570)	(532,554)		(680,100)	(466,275)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax						(122,971)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		4,265	4,387		12,795	61,079
Total other comprehensive income (loss)		4,265	4,387		12,795	(61,892)
Balance		(667,305)	(528,167)		(667,305)	(528,167)
Accumulated Other Comprehensive Income (Loss) [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Balance	[1]	(725,386)	(592,597)		(746,448)	(516,011)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		14,515	15,655		29,146	(115,886)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		4,702	4,307		11,133	59,262
Total other comprehensive income (loss)		19,217	19,962		40,279	(56,624)
Balance		$ (706,169)	$ (572,635)	[1]	$ (706,169)	$ (572,635)	[1]
[1]	As adjusted; refer to Note 1.

Segments - Additional Informati

Segments - Additional Information (Details) $ in Thousands	3 Months Ended			9 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)		Dec. 31, 2020USD ($)Segment	Dec. 31, 2019USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment				2
Net sales	$ 425,994	$ 704,666	[1]	$ 1,402,886	$ 2,207,007	[1]
Foreign Sales [Member]
Segment Reporting Information [Line Items]
Net sales	$ 78,440	$ 164,832		$ 267,370	$ 526,130
[1]	As adjusted; refer to Note 1.

Segments - Schedule of Selected

Segments - Schedule of Selected Financial Information for Each Reportable Segment and Reconciliation of EBITDAP to Operating Income (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended				9 Months Ended
		Sep. 30, 2019	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019		Dec. 31, 2020	Dec. 31, 2019		Mar. 31, 2020	[1]
Segment Reporting Information [Line Items]
Net sales to external customers			$ 425,994		$ 704,666	[1]	$ 1,402,886	$ 2,207,007	[1]
Segment profit and reconciliation to consolidated income before income taxes:
Adjusted EBITDAP			61,407		89,272		131,067	250,126
Reconciliation of segment profit to income (loss) before income taxes
Depreciation and amortization			(22,119)		(29,843)	[1]	(72,819)	(104,112)	[1]
Interest expense and other, net			(44,881)		(33,178)	[1]	(132,344)	(96,069)	[1]
Corporate expenses			(8,483)		(13,848)		(42,027)	(42,709)
Share-based compensation expense			(3,679)		(2,955)		(9,086)	(8,245)
Loss on sale of assets and businesses		$ 10,000	(45,273)		(60,019)	[1]	(46,020)	(55,190)	[1]
Amortization of acquired contract liabilities			6,867		16,597		35,017	56,153
Non-service defined benefit income			12,432		14,799	[1]	37,275	56,025	[1]
Union represented employee incentives					(1,400)			(7,071)
Legal judgment gain, net	[1]				3,857			9,257
Impairment of long-lived assets				$ (252,382)			(252,382)
Impairment of rotable inventory			(23,689)				(23,689)
Loss before income taxes			(67,418)		(16,718)		(375,008)	58,165
Total capital expenditures			6,184		10,255		18,988	27,250
Total assets			2,401,922				2,401,922			$ 2,980,333
Systems & Support [Member]
Segment Reporting Information [Line Items]
Intersegment sales (eliminated in consolidation)			482		1,717		2,888	4,118
Reconciliation of segment profit to income (loss) before income taxes
Amortization of acquired contract liabilities			4,306		8,377		11,569	26,126
Aerospace Structures [Member]
Segment Reporting Information [Line Items]
Intersegment sales (eliminated in consolidation)			54		1,513		1,469	5,106
Reconciliation of segment profit to income (loss) before income taxes
Amortization of acquired contract liabilities			2,561		8,220		23,448	30,027
Corporate & Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales to external customers			(536)		(3,230)		(4,357)	(9,224)
Reconciliation of segment profit to income (loss) before income taxes
Depreciation and amortization			(989)		(847)		(2,652)	(2,533)
Total capital expenditures			158		416		801	980
Total assets			451,824				451,824
Operating Segments [Member] | Systems & Support [Member]
Segment Reporting Information [Line Items]
Net sales to external customers			263,638		337,207		755,290	1,001,384
Segment profit and reconciliation to consolidated income before income taxes:
Adjusted EBITDAP			46,746		57,132		110,983	162,008
Reconciliation of segment profit to income (loss) before income taxes
Depreciation and amortization			(8,353)		(8,075)		(24,830)	(24,314)
Total capital expenditures			2,308		3,929		11,819	12,355
Total assets			1,463,017				1,463,017
Operating Segments [Member] | Aerospace Structures [Member]
Segment Reporting Information [Line Items]
Net sales to external customers			162,356		367,459		647,596	1,205,623
Segment profit and reconciliation to consolidated income before income taxes:
Adjusted EBITDAP			14,661		32,140		20,084	88,118
Reconciliation of segment profit to income (loss) before income taxes
Depreciation and amortization			(12,777)		(20,921)		(45,337)	(77,265)
Total capital expenditures			3,718		$ 5,910		6,368	$ 13,915
Total assets			$ 487,081				$ 487,081
[1]	As adjusted; refer to Note 1.

Restructuring - Additional Info

Restructuring - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended			12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	[1]	Dec. 31, 2020	Dec. 31, 2019	[1]	Mar. 31, 2021
Restructuring Cost And Reserve [Line Items]
Restructuring	$ 4,071	$ 4,744		$ 32,747	$ 13,490
Systems & Support [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring				5,725
Aerospace Structures [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring				20,580
Aerospace Structures [Member] | Facility Closures [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring				13,097
Corporate Headquarters [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring				$ 6,442
Forecast [Member]
Restructuring Cost And Reserve [Line Items]
Consulting and severance costs							$ 34,000
[1]	As adjusted; refer to Note 1.