CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Operating Activities
Net income	$ 272,241	$ 263,204	$ 313,711
Adjustments to net income to arrive at cash provided by operating activities:
Depreciation	94,903	98,037	100,041
Amortization of intangible assets	11,159	10,848	11,145
Amortization of debt discount	6,875	12,293	17,168
Amortization of deferred financing costs	3,847	4,764	5,157
Loss on extinguishment of debt	11,773	0	0
Deferred income taxes	(16,591)	7,518	23,018
(Gain) loss on disposal of property	(1,613)	(2,928)	2,281
Share-based plans expense	12,025	6,724	9,740
Excess tax benefits from share-based plans	(2)	(23)	(540)
Changes in assets and liabilities:
Net receivables	34,602	(207,451)	(153,723)
Net inventories	(56,569)	(16,466)	(6,400)
Accounts payable	4,160	42,557	20,065
Contract advances and allowances	(333)	(2,103)	15,108
Accrued compensation	13,200	(25,063)	(53,616)
Accrued income taxes	(26,042)	19,801	(40,164)
Pension and other postretirement benefits	(33,438)	37,547	86,955
Other assets and liabilities	(56,605)	123,048	71,124
Cash provided by operating activities	273,592	372,307	421,070
Investing Activities
Capital expenditures	(96,889)	(122,292)	(130,201)
Acquisition of business, net of cash acquired	0	0	(172,251)
Proceeds from the disposition of property, plant, and equipment	172	7,335	3,001
Cash used for investing activities	(96,717)	(114,957)	(299,451)
Financing Activities
Payments made on bank debt	(35,000)	(20,000)	(13,438)
Payments made to extinguish debt	(409,000)	(300,000)	(537,576)
Proceeds from issuance of long-term debt	200,000	0	750,000
Payments made for debt issue costs	(1,458)	0	(19,883)
Purchase of treasury shares	(58,371)	(49,991)	0
Dividends paid	(30,033)	(26,552)	(6,700)
Proceeds from employee stock compensation plans	5,461	5,709	13,819
Excess tax benefits from share-based plans	2	23	540
Cash (used for) provided by financing activities	(328,399)	(390,811)	186,762
(Decrease) increase in cash and cash equivalents	(151,524)	(133,461)	308,381
Cash and cash equivalents at beginning of year	568,813	702,274	393,893
Cash and cash equivalents at end of year	417,289	568,813	702,274
Noncash investing activity:
Capital expenditures included in accounts payable	14,549	14,976	14,118
Property disposals included in accounts receivable	5,177	0	0
Noncash Financing Activity [Abstract]
Treasury Shares purchased included in other accrued liabilities	$ 1,140	$ 0	$ 0