Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flow from operating activities:
Net earnings	$ 189,989	$ 179,234
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	128,127	110,049
Amortization of deferred policy acquisition costs	5,899	7,050
Change in allowance for losses on trade receivables	(3)	(16)
Change in allowance for inventory reserves	1,705	2,008
Net of gains on sale of real and personal property	(13,048)	(17,627)
Net (gain) loss on sale of investments	238	(4,880)
Deferred income taxes	24,926	89,129
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	33,416	(21,953)
Inventories	(1,629)	177
Prepaid expenses	422	8,702
Capitalization of deferred policy acquisition costs	(24,489)	(9,010)
Other assets	19,770	21,973
Related party assets	140,587	5,644
Accounts payable and accrued expenses	45,412	11,327
Policy benefits and losses, claims and loss expenses payable	(17,413)	35,857
Other policyholders' funds and liabilities	4,130	(3,142)
Deferred income	(671)	4,558
Related party liabilities	2,095	268
Net cash provided by operating activities	539,463	419,348
Purchase of:
Property, plant and equipment	(280,986)	(348,331)
Short term investments	(150,987)	(139,207)
Equity securities	(26)	(9,056)
Real estate	(792)	(5,146)
Mortgage loans	(50,828)	(65,612)
Proceeds from sale of:
Property, plant and equipment	132,597	110,289
Short term investments	154,549	154,060
Equity securities	0	10,210
Real estate	590	109
Mortgage loans	12,700	29,722
Net cash used by investing activities	(310,285)	(302,704)
Cash flow from financing activities:
Borrowings from credit facilities	88,847	178,292
Principal repayments on credit facilities	(171,496)	(99,102)
Debt issuance costs	(1,010)	(1,316)
Capital lease payments	(9,883)	(3,505)
Leveraged Employee Stock Ownership Plan - repayments from loan	316	556
Securitization deposits	(1,729)	38,428
Preferred stock redemption paid	0	(144,289)
Preferred stock dividends paid	0	(2,913)
Contribution to related party	0	(518)
Investment contract deposits	169,933	6,228
Investment contract withdrawals	(15,275)	(15,419)
Net cash used by financing activities	59,703	(43,558)
Effects of exchange rate on cash	(240)	(389)
Increase (decrease) in cash and cash equivalents	288,641	72,697
Cash and cash equivalents at the end of period	357,180	382,514
Cash and cash equivalents at the end of the period	645,821	455,211
Fixed maturities investments
Purchase of:
Payments to acquire investments	(179,941)	(136,371)
Proceeds from sale of:
Proceeds from sale of acquired investments	52,586	97,010
Preferred stock investments
Purchase of:
Payments to acquire investments	(1,200)	(1,633)
Proceeds from sale of:
Proceeds from sale of acquired investments	$ 1,453	$ 1,252