Employee Benefit Plans (Details) $ in Thousands		9 Months Ended		12 Months Ended
	Feb. 09, 2015 USD ($)	Dec. 31, 2015 USD ($) plan		Mar. 31, 2015 USD ($)		Mar. 31, 2014 USD ($)	Oct. 04, 2015 USD ($)	Jul. 03, 2015 USD ($)	Dec. 28, 2014 USD ($)	Sep. 28, 2014 USD ($)	Jun. 29, 2014 USD ($)
Defined Benefit Plans
Reduction in pension liabilities transferred due to spin-off		$ 223,790
Reduction of pension assets to spin-off		163,034
Reduction of accumulated other comprehensive income due to transfer to spin-off		97,764
Reduction of PRB liabilities due to transfer to Vista Outdoor		1,963
Reduction in AOCI for PRB benefits due to transfer to Vista Outdoor		$ 1,727
Number of pension plans acquired | plan		2
Actuarial losses using Scale MP 2014				$ 189,000
Actuarial losses for pension benefits and other postretirement benefits				13,000
Change in plan assets
Employer contributions		$ 41,028		51,205		$ 48,379
Amounts Recognized in the Balance Sheet
Pension liabilities		(761,632)	[1]	(851,001)	[1]		$ (811,459)	$ (845,562)	$ (439,469)	$ (490,664)	$ (518,744)
Pension Benefits
Defined Benefit Plans
Decrease in projected benefit obligation		$ 2,295
Interest credit, percent		4.00%
Accumulated benefit obligation		$ 2,952,599		3,197,143
Change in benefit obligation
Benefit obligation at beginning of year		3,199,221		2,988,288
Service cost		14,445		23,182		34,763
Interest cost		91,044		129,236		130,253
Plan Amendments		(2,295)		0
Actuarial loss (gain)		(211,581)		465,524
Retiree contributions		0		0
Benefits paid		(138,166)		(192,756)
Impact of Distribution		0		(223,790)
Merger with Orbital Sciences		0		9,537
Benefit obligation at end of year		2,952,668		3,199,221		2,988,288
Change in plan assets
Fair value of plan assets at beginning of year		2,348,795		2,426,013
Actual return on plan assets		(94,573)		177,776
Retiree contributions		0		0
Employer contributions		73,844		87,150
Benefits paid		(138,166)		(192,756)
Fair value of assets at February 9, 2015, transferred to Vista Outdoor (2)		0		(163,034)
Merger with Orbital Sciences		0		13,646
Fair value of plan assets at end of year		2,189,900		2,348,795		2,426,013
Funded status		(762,768)		(850,426)
Amount transferred to Vista Outdoor	$ 158,514
Gain / loss on plan assets	$ 163,034
Amounts Recognized in the Balance Sheet
Noncurrent assets		4,264		4,318
Other current liabilities		(5,400)		(3,743)
Postretirement and postemployment benefit liabilities		0		0
Pension liabilities		(761,632)		(851,001)
Net amount recognized		(762,768)		(850,426)
Accumulated other comprehensive loss (income) related to:
Unrecognized net actuarial losses		1,407,947		1,520,459
Unrecognized prior service benefit		(131,068)		(144,410)
Accumulated other comprehensive loss (income)		1,276,879		1,376,049
Estimated amount that will be amortized from accumulated other comprehensive loss into net periodic benefit cost in fiscal 2013
Recognized net actuarial losses		123,195
Amortization of prior service benefits		(20,605)
Total		102,590
Information for Pension Plans with an Accumulated Benefit Obligation in Excess of Plan Assets
Projected benefit obligation		2,952,668		3,189,805
Accumulated benefit obligation		2,952,599		3,187,727
Fair value of plan assets		$ 2,189,900		2,335,060
Pension Benefits | Minimum
Defined Benefit Plans
Vesting period (in years)		3 years
Pension Benefits | Maximum
Defined Benefit Plans
Vesting period (in years)		5 years
Other Postretirement Benefits
Change in benefit obligation
Benefit obligation at beginning of year		$ 131,620		128,065
Service cost		1		3		9
Interest cost		3,378		4,803		5,207
Plan Amendments		0		0
Actuarial loss (gain)		(13,106)		12,255
Retiree contributions		3,302		4,729
Benefits paid		(10,858)		(16,272)
Impact of Distribution		0		(1,963)
Merger with Orbital Sciences		0		0
Benefit obligation at end of year		114,337		131,620		128,065
Change in plan assets
Fair value of plan assets at beginning of year		63,678		61,055
Actual return on plan assets		(1,716)		4,397
Retiree contributions		3,302		4,729
Employer contributions		5,644		9,769
Benefits paid		(10,858)		(16,272)
Fair value of assets at February 9, 2015, transferred to Vista Outdoor (2)		0		0
Merger with Orbital Sciences		0		0
Fair value of plan assets at end of year		60,050		63,678		$ 61,055
Funded status		(54,287)		(67,942)
Amounts Recognized in the Balance Sheet
Noncurrent assets		0		0
Other current liabilities		(3,381)		(3,436)
Postretirement and postemployment benefit liabilities		(50,906)		(64,506)
Pension liabilities		0		0
Net amount recognized		(54,287)		(67,942)
Accumulated other comprehensive loss (income) related to:
Unrecognized net actuarial losses		15,795		25,906
Unrecognized prior service benefit		(9,724)		(15,163)
Accumulated other comprehensive loss (income)		6,071		$ 10,743
Estimated amount that will be amortized from accumulated other comprehensive loss into net periodic benefit cost in fiscal 2013
Recognized net actuarial losses		1,589
Amortization of prior service benefits		(5,162)
Total		$ (3,573)
Other Postretirement Benefits | Minimum
Defined Benefit Plans
Age for eligibility for pre and/or post 65 healthcare company subsidy and retiree life insurance coverage (in years)		50 years
Term of service for eligibility for pre and/or post 65 healthcare company subsidy and retiree life insurance coverage (in years)		5 years
Other Postretirement Benefits | Maximum
Defined Benefit Plans
Age for eligibility for pre and/or post 65 healthcare company subsidy and retiree life insurance coverage (in years)		55 years
Term of service for eligibility for pre and/or post 65 healthcare company subsidy and retiree life insurance coverage (in years)		10 years
Change in Assumptions for Pension Plans | Pension Benefits
Change in benefit obligation
Actuarial loss (gain)		$ (50,000)
Change in Assumptions for Pension Plans | Other Postretirement Benefits
Change in benefit obligation
Actuarial loss (gain)		$ (4,000)

[1] See Note 2 - Restatement