Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Cash flow from operating activities:
Net earnings	$ 342,391	$ 264,708	$ 205,367
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	293,169	260,492	229,789
Amortization of deferred policy acquisition costs	19,982	17,376	13,791
Change in allowance for losses on trade receivables	(36)	(134)	(208)
Change in allowance for inventory reserves	871	1,133	1,382
Net gain on sale of real and personal property	(33,557)	(22,496)	(20,888)
Net (gain) loss on sale of investments	(6,411)	(8,323)	(5,579)
Deferred income taxes	46,371	13,518	104,360
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	62,506	36,322	(77,115)
Inventories	(11,495)	1,206	(173)
Prepaid expenses	2,186	(15,587)	15,748
Capitalization of deferred policy acquisition costs	(32,611)	(50,640)	(23,166)
Other assets	7,667	21,556	5,992
Related party assets	7,554	133,672	(14,210)
Accounts payable and accrued expenses	34,731	40,032	19,469
Policy benefits and losses, claims and loss expenses payable	(30,496)	(30,478)	212,330
Other policyholders' funds and liabilities	693	21	(1,458)
Deferred income	1,259	(1,312)	4,367
Related party liabilities	4,730	464	44
Net cash provided by operating activities	709,504	661,530	669,842
Purchase of:
Property, plant and equipment	(999,365)	(655,984)	(589,799)
Short term investments	(270,690)	(411,638)	(291,622)
Fixed maturities investments	(282,424)	(443,262)	(220,104)
Equity securities	(1,562)	(16,289)	(9,048)
Preferred stock	(640)	(6,296)	(2,717)
Real estate	(532)	(1,073)	(7,829)
Mortgage loans	(52,419)	(80,711)	(127,163)
Proceeds from sale and paydowns of:
Property, plant and equipment	270,053	220,699	168,912
Short term investments	269,052	417,520	300,893
Fixed maturities investments	138,401	160,806	128,486
Equity securities	29,139	372	10,222
Preferred stock	6,004	7,258	2,352
Real estate	544	671	440
Mortgage loans	48,686	95,714	54,840
Net cash used by investing activities	(845,753)	(712,213)	(582,137)
Cash flow from financing activities:
Borrowings from credit facilities	431,029	270,546	237,780
Principal repayments on credit facilities	(293,068)	(257,957)	(201,888)
Debt issuance costs	(3,943)	(2,223)	(2,004)
Capital lease payments	(53,079)	(26,877)	(8,328)
Leveraged Employee Stock Ownership Plan - Repayments from loan	487	692	984
Securitization deposits		1,195	42,088
Preferred stock redemption paid			(144,289)
Preferred stock dividends paid			(2,913)
Common stock dividends paid	(19,568)	(97,421)	(19,484)
Contribution to related party			(518)
Investment contract deposits	140,613	301,729	13,854
Investment contract withdrawals	(34,677)	(31,901)	(28,027)
Net cash used by financing activities	167,794	157,783	(112,745)
Effects of exchange rate on cash	(177)	(536)	(294)
Increase (decrease) in cash and cash equivalents	31,368	106,564	(25,334)
Cash and cash equivalents at the beginning of period	463,744	357,180	382,514
Cash and cash equivalents at the end of the period	$ 495,112	$ 463,744	$ 357,180