SEGMENTS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2019
Financial information of reportable segment and the reconciliation of EBITDA to operating income
Costs and Expenses	$ 703,005	$ 824,828	$ 2,108,798	$ 2,581,385
Gain (Loss) on Disposition of Business	(60,019)	0	(55,190)	(17,837)
Operating Income (Loss)	1,661	(16,933)	98,209	(85,482)
Employee Benefits and Share-based Compensation	(2,955)	(3,266)	(8,245)	(8,509)
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	(13,989)	(16,520)	(57,280)	(49,581)
Interest expense and other	33,178	29,309	96,069	83,515
Income (loss) from continuing operations before income taxes	(17,528)	(29,722)	59,420	(119,416)
Depreciation and amortization	29,843	37,404	104,112	114,349
Amortization of Acquired Contract Liabilities	16,597	14,731	56,153	48,769
EBITDA	72,469	5,740	199,172	85,176
Capital expenditures	10,255	10,570	27,250	34,824
Total assets	2,625,386		2,625,386		$ 2,854,574
Revenues	704,666	807,895	2,207,007	2,495,903
Integrated Systems [Member]
Financial information of reportable segment and the reconciliation of EBITDA to operating income
Operating Income (Loss)	47,896	39,947	134,140	115,221
Depreciation and amortization	6,992	7,376	21,042	22,316
Amortization of Acquired Contract Liabilities	8,377	8,172	26,126	25,789
EBITDA	46,511	39,151	129,056	111,748
Capital expenditures	2,974	3,951	9,734	9,388
Total assets	1,277,654		1,277,654		1,215,350
Revenues	275,248	252,437	813,454	754,193
Aerospace Structures [Member]
Financial information of reportable segment and the reconciliation of EBITDA to operating income
Operating Income (Loss)	18,039	(49,813)	43,930	(152,143)
Depreciation and amortization	20,921	27,673	77,265	84,888
Amortization of Acquired Contract Liabilities	8,220	6,559	30,027	22,980
EBITDA	32,140	(28,699)	88,118	(2,994)
Capital expenditures	5,910	5,722	13,915	22,937
Total assets	1,005,460		1,005,460		1,257,039
Revenues	368,972	490,337	1,210,729	1,551,090
Product Support [Member]
Financial information of reportable segment and the reconciliation of EBITDA to operating income
Operating Income (Loss)	9,538	11,421	29,680	30,604
Depreciation and amortization	1,083	1,611	3,272	4,944
EBITDA	10,621	13,032	32,952	35,548
Capital expenditures	955	852	2,621	1,871
Total assets	276,717		276,717		271,813
Revenues	63,978	71,446	193,127	209,860
Elimination of inter-segment sales
Financial information of reportable segment and the reconciliation of EBITDA to operating income
Revenues	(3,532)	(6,325)	(10,303)	(19,240)
Corporate
Financial information of reportable segment and the reconciliation of EBITDA to operating income
Operating Income (Loss)	(70,857)	(15,222)	(101,296)	(70,655)
Depreciation and amortization	847	744	2,533	2,201
EBITDA	(16,803)	(17,744)	(50,954)	(59,126)
Capital expenditures	416	45	980	628
Total assets	65,555		65,555		110,372
Guarantor Subsidiaries [Member]
Financial information of reportable segment and the reconciliation of EBITDA to operating income
Costs and Expenses	579,107	741,002	1,845,169	2,309,008
Gain (Loss) on Disposition of Business	0	0	10,121	(947)
Operating Income (Loss)	67,091	(5,249)	182,480	(22,076)
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	(13,485)	(16,188)	(55,788)	(48,562)
Interest expense and other	5,871	4,007	17,423	13,334
Income (loss) from continuing operations before income taxes	42,700	(30,552)	122,548	(99,129)
Depreciation and amortization	26,089	32,640	93,109	99,302
Capital expenditures			22,874	30,398
Total assets	2,047,869		2,047,869		$ 2,419,798
Revenues	646,198	735,753	2,027,649	2,286,932
Non-US [Member]
Financial information of reportable segment and the reconciliation of EBITDA to operating income
Revenues	$ 164,832	$ 245,505	$ 526,130	$ 736,501