CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 2012
Income Statement [Abstract]
Sales	$ 1,142,381	$ 1,069,787	$ 2,221,122	$ 2,152,089
Cost of sales	874,955	841,520	1,711,685	1,674,199
Gross profit	267,426	228,267	509,437	477,890
Operating expenses:
Research and development	11,801	15,914	22,226	29,921
Selling	46,899	39,609	89,664	80,136
General and administrative	60,460	62,187	123,658	126,588
Income before interest, loss on extinguishment of debt, income taxes, and noncontrolling interest	148,266	110,557	273,889	241,245
Interest expense	(15,242)	(18,098)	(29,132)	(37,913)
Interest income	23	123	91	187
Gains (Losses) on Extinguishment of Debt	0	(11,773)	0	(11,773)
Income before income taxes and noncontrolling interest	133,047	80,809	244,848	191,746
Income tax provision	40,376	15,640	80,037	55,637
Net income	92,671	65,169	164,811	136,109
Less net income attributable to noncontrolling interest	80	108	183	220
Net income attributable to Alliant Techsystems Inc.	92,591	65,061	164,628	135,889
Alliant Techsystems Inc. earnings per common share:
Basic (in dollars per share)	$ 2.92	$ 2.01	$ 5.18	$ 4.18
Diluted (in dollars per share)	$ 2.86	$ 2.00	$ 5.10	$ 4.16
Cash dividends paid per share (in dollars per share)	$ 0.26	$ 0.20	$ 0.52	$ 0.40
Alliant Techsystems Inc. weighted-average number of common shares outstanding:
Basic (in shares)	31,671	32,406	31,781	32,519
Diluted (in shares)	32,385	32,591	32,256	32,685
Other comprehensive income (loss), net of tax:
Net Income (from above)	92,671	65,169	164,811	136,109
Pension and other postretirement benefit liabilities:
Reclassification of prior service credits for pension and postretirement benefit plans recorded to net income, net of tax benefit of $2,790, $841, $5,620, and $1,683	(4,552)	(1,352)	(9,063)	(2,703)
Reclassification of net actuarial loss for pension and postretirement benefit plans recorded to net income, net of tax expense of $(14,077), $(12,297), and $(28,396) $(24,619)	22,968	19,501	45,694	39,041
Valuation adjustment for pension and postretirement benefit plans, net of tax (expense) benefit of $0, $0, $0, and $(732)	0	0	0	1,268
Change in fair value of derivatives, net of tax benefit (expense) of $(2,097), $(1,971), $1,721 and $847, respectively	3,222	3,073	(2,759)	(1,334)
Change in fair value of available-for-sale securities, net of tax benefit of $52, $91, $64, and $148, respectively	(83)	(142)	(103)	(232)
Total other comprehensive income	21,555	21,080	33,769	36,040
Comprehensive income	114,226	86,249	198,580	172,149
Less comprehensive income attributable to noncontrolling interest	80	108	183	220
Comprehensive income attributable to Alliant Techsystems Inc.	$ 114,146	$ 86,141	$ 198,397	$ 171,929