RESTRUCTURING COSTS RESTRUCTURING COSTS (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2018 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 2,327	$ 6,531	$ 18,206	$ 36,289	$ 195,300
Restructuring and Related Cost, Expected Cost	204,400		204,400
Restructuring and Related Cost, Expected Cost Remaining	9,100		9,100
2017 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Activities, Reduction of Square Footage		4,300,000		4,300,000
Restructuring and Related Activities, Reduction to Workforce		2,500		2,500
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	960	$ 1,147	14,951	$ 1,894
Restructuring and Related Cost, Expected Cost	39,000		39,000
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	1,076	474	2,460	8,335
Restructuring and Related Cost, Expected Cost	32,200		32,200
Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	20,700		20,700
Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	36,200		36,200
Accelerated Depreciation [Member] | Depreciation and Amortization [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	382	0	2,538
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	291	4,528	795	23,522
Restructuring and Related Cost, Expected Cost	76,300		76,300
Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	2,327	6,149	18,206	33,751
Integrated Systems [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	2,150	1,337	5,206	3,678
Integrated Systems [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	783	26	1,951	26
Integrated Systems [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	1,076	0	2,460	70
Integrated Systems [Member] | Accelerated Depreciation [Member] | Depreciation and Amortization [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	382	0	1,909
Integrated Systems [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	291	929	795	1,673
Integrated Systems [Member] | Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	2,150	955	5,206	1,769
Aerospace Structures [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	177	2,793	10,070	14,743
Aerospace Structures [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	177	1,121	10,070	1,868
Aerospace Structures [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	474	0	8,265
Aerospace Structures [Member] | Accelerated Depreciation [Member] | Depreciation and Amortization [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	0	0	629
Aerospace Structures [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	1,198	0	3,981
Aerospace Structures [Member] | Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	177	2,793	10,070	14,114
Product Support [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	19	163	779
Product Support [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	0	163	0
Product Support [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	0	0	0
Product Support [Member] | Accelerated Depreciation [Member] | Depreciation and Amortization [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	0	0	0
Product Support [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	19	0	779
Product Support [Member] | Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	19	163	779
Corporate Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	2,382	2,767	17,089
Corporate Segment [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	0	2,767	0
Corporate Segment [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	0	0	0
Corporate Segment [Member] | Accelerated Depreciation [Member] | Depreciation and Amortization [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0			0
Corporate Segment [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	2,382	0	17,089
Corporate Segment [Member] | Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 0	2,382	$ 2,767	17,089
Minimum [Member] | 2017 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost		195,000		195,000
Maximum [Member] | 2017 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost		$ 210,000		$ 210,000