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.