Goodwill, Net Intangibles and Other Noncurrent Assets (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Jul. 04, 2015		Mar. 31, 2015		Dec. 31, 2015		Dec. 31, 2015		Mar. 31, 2015		Mar. 31, 2014		Oct. 04, 2015	Jul. 03, 2015	Dec. 28, 2014	Sep. 28, 2014	Jun. 29, 2014
Changes in the carrying amount of goodwill
Balance at the beginning of the period	$ 1,862,255	[1]			$ 1,862,255	[1]			$ 1,039,763
Goodwill									856,792
Impairment	0		$ (34,300)		0	[2],[3]			(34,300)	[2],[3]	$ (3,700)	[2],[3]
Measurement period adjustments					(33,889)
Balance at the end of the period			1,862,255	[1]	1,828,366	[1]	$ 1,828,366	[1]	1,862,255	[1]	1,039,763
Deferred charges and other non-current assets
Parts inventory			9,973		10,303		10,303		9,973
Environmental remediation receivable			23,771		15,145		15,145		23,771
Derivative contracts			4,105		1,105		1,105		4,105
Tax refund receivable			38,392		42,555		42,555		38,392
Other noncurrent assets			66,220		70,354		70,354		66,220
Total other noncurrent assets			142,461	[1]	139,462	[1]	139,462	[1]	142,461	[1]			$ 131,354	$ 135,678	$ 108,954	$ 110,075	$ 109,543
Flight Systems Group
Changes in the carrying amount of goodwill
Balance at the beginning of the period	797,526				797,526				530,869
Goodwill									266,657
Impairment									0
Measurement period adjustments					125,465
Balance at the end of the period			797,526		922,991		922,991		797,526		530,869
Defense Systems Group
Changes in the carrying amount of goodwill
Balance at the beginning of the period	363,247				363,247				363,247
Goodwill									0
Impairment							(3,700)		0
Measurement period adjustments					0
Balance at the end of the period			363,247		363,247		363,247		363,247		363,247
Space Systems Group
Changes in the carrying amount of goodwill
Balance at the beginning of the period	$ 701,482				701,482				145,647
Goodwill									590,135
Impairment									(34,300)
Measurement period adjustments					(159,354)
Balance at the end of the period			$ 701,482		542,128		542,128		$ 701,482		$ 145,647
Accumulated impairment losses					$ 142,800		$ 142,800

[1] See Note 2 - Restatement

[2] See Note 2 - Restatement

[3] See Note 2 - Restatement