Revenue Recognition and Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 4,142,321		$ 4,142,321
Amortization of Acquired Contract Liabilities	16,597	$ 14,731	56,153	$ 48,769
Revenues	704,666	807,895	2,207,007	2,495,903
Integrated Systems [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	265,006	241,578	782,457	720,926
Amortization of Acquired Contract Liabilities	8,377	8,172	26,126	25,789
Revenues	275,248	252,437	813,454	754,193
Integrated Systems [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	76,267	66,208	224,442	205,379
Integrated Systems [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	188,739	175,370	558,015	515,547
Integrated Systems [Member] | Total - Timing of Transfer [Member]
Disaggregation of Revenue [Line Items]
Revenues	273,383	249,750	808,583	746,715
Aerospace Structures [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	359,239	482,417	1,175,596	1,522,758
Amortization of Acquired Contract Liabilities	8,220	6,559	30,027	22,980
Revenues	368,972	490,337	1,210,729	1,551,090
Aerospace Structures [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	330,657	434,870	1,075,141	1,385,368
Aerospace Structures [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	28,582	47,547	100,455	137,390
Aerospace Structures [Member] | Total - Timing of Transfer [Member]
Disaggregation of Revenue [Line Items]
Revenues	367,459	488,976	1,205,623	1,545,738
Product Support [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	63,824	69,169	192,801	203,450
Revenues	63,978	71,446	193,127	209,860
Product Support [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	58,962	64,942	179,383	189,174
Product Support [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,862	4,227	13,418	14,276
Product Support [Member] | Total - Timing of Transfer [Member]
Disaggregation of Revenue [Line Items]
Revenues	63,824	69,169	192,801	203,450
Customer [Domain] | Integrated Systems [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	145,026	124,453	413,263	378,117
Customer [Domain] | Aerospace Structures [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	208,943	230,556	681,471	756,661
Customer [Domain] | Product Support [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	47,206	53,596	148,552	158,158
Military [Member] | Integrated Systems [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	93,405	87,486	277,009	258,488
Military [Member] | Aerospace Structures [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	27,394	54,275	83,773	178,679
Military [Member] | Product Support [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	12,455	11,383	32,726	32,637
Business Jet [Member] | Integrated Systems [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	10,358	16,369	43,897	43,939
Business Jet [Member] | Aerospace Structures [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	98,370	181,511	330,178	541,520
Business Jet [Member] | Product Support [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	418	350	1,383	2,143
Regional [Member] | Integrated Systems [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	8,166	7,048	24,026	21,004
Regional [Member] | Aerospace Structures [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	24,523	7,807	80,155	24,342
Regional [Member] | Product Support [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	3,144	3,840	9,408	10,512
Nonaviation [Member] | Integrated Systems [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	8,051	6,222	24,262	19,378
Nonaviation [Member] | Aerospace Structures [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	9	8,268	19	21,556
Nonaviation [Member] | Product Support [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	601	0	732	0
Total - Customer [Member] | Integrated Systems [Member]
Disaggregation of Revenue [Line Items]
Revenues	273,383	249,750	808,583	746,715
Total - Customer [Member] | Aerospace Structures [Member]
Disaggregation of Revenue [Line Items]
Revenues	367,459	488,976	1,205,623	1,545,738
Total - Customer [Member] | Product Support [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 63,824	$ 69,169	$ 192,801	$ 203,450