Consolidating financial information by industry segment (Cash Flow Statements) (Details) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
		Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Cash flow from operating activities:
Net earnings		$ 183,379		$ 156,247		$ 354,664		$ 280,721
Earnings from consolidated entities
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation						$ 192,865		$ 172,617
Amortization of deferred policy acquisition costs		5,643		4,290		10,421		8,474
Change in allowance for losses on trade receivables						(9)		(219)
Change in allowance for inventory reserves						(603)		(960)
Net gain on sale of real and personal property		(32,821)		(21,541)		(78,805)		(44,500)
Net (gain) loss on sale of investments						(3,022)		(2,788)
Deferred income tax						27,259		23,212
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables						13,618		13,396
Inventories						(2,107)		(1,260)
Prepaid expenses						71,813		14,012
Capitalization of deferred policy acquisition costs						(15,636)		(13,728)
Other assets						18,306		(7,885)
Related party assets						57,767		2,170
Accounts payable and accrued expenses						59,525		36,410
Policy benefits and losses, claims and loss expenses payable						11,702		(3,918)
Other policyholders' funds and liabilities						2,684		1,156
Deferred income						2,339		1,962
Related party liabilities						(97)		375
Net cash provided by operating activities						722,684		479,247
Cash flow from investing activities:
Property, plant and equipment						(720,265)		(599,351)
Short term investments						(249,082)		(130,294)
Fixed maturities investments						(169,899)		(114,112)
Equity securities						(1,315)		(3,707)
Preferred stock						(3)		(3)
Real estate						(23)		(11,312)
Mortgage loans						(86,361)		(21,189)
Proceeds from sale of:
Property, plant and equipment						379,198		260,659
Short term investments						243,634		130,326
Fixed maturities investments						89,085		48,955
Equity securities						$ 808		3,030
Preferred stock								1,000
Real estate								401
Mortgage loans						$ 29,895		18,623
Net cash used by investing activities						(484,328)		(416,974)
Cash flow from financing activities:
Borrowings from credit facilities						461,735		506,792
Principal repayments on credit facilities						(187,958)		(208,101)
Debt issuance costs						(5,957)		(9,847)
Capital lease payments						(77,786)		(40,694)
Employee Stock Ownership Plan						(1,484)		$ (124)
Securitization deposits						298
Common stock dividends paid						(19,594)
Investment contract deposits						150,704		$ 71,571
Investment contract withdrawals						(25,974)		(24,075)
Net cash provided by (used in) financing activities						293,984		295,522
Effects of exchange rate on cash						(12,543)		(3,761)
Increase (decrease) in cash and cash equivalents						519,797		354,034
Cash and cash equivalents at the beginning of period						441,850		495,112
Cash and cash equivalents at the end of the period		961,647		849,146		961,647		849,146
Operating Segments [Member] | Moving and Storage Consolidations [Member]
Cash flow from operating activities:
Net earnings		$ 183,379		$ 156,247		354,664		280,721
Earnings from consolidated entities						(16,129)		(15,675)
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation						$ 192,865		$ 172,617
Amortization of deferred policy acquisition costs
Change in allowance for losses on trade receivables						$ (21)		$ (209)
Change in allowance for inventory reserves						(603)		(960)
Net gain on sale of real and personal property						$ (78,805)		$ (44,500)
Net (gain) loss on sale of investments
Deferred income tax						$ 23,125		$ 18,872
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables						1,021		(1,605)
Inventories						(2,107)		(1,260)
Prepaid expenses						$ 71,813		$ 14,012
Capitalization of deferred policy acquisition costs
Other assets						$ 17,121		$ (7,829)
Related party assets						58,373		3,172
Accounts payable and accrued expenses						51,340		30,308
Policy benefits and losses, claims and loss expenses payable						$ 20,648		$ 8,241
Other policyholders' funds and liabilities
Deferred income						$ 2,339		$ 1,962
Related party liabilities						(26)		629
Net cash provided by operating activities						695,618		458,496
Cash flow from investing activities:
Property, plant and equipment						$ (720,265)		$ (599,351)
Short term investments
Fixed maturities investments
Equity securities
Preferred stock
Real estate
Mortgage loans						$ (11,748)		$ (5,465)
Proceeds from sale of:
Property, plant and equipment						$ 379,198		$ 260,659
Short term investments
Fixed maturities investments
Equity securities
Preferred stock
Real estate
Mortgage loans						$ 10,011		$ 10,088
Net cash used by investing activities						(342,804)		(334,069)
Cash flow from financing activities:
Borrowings from credit facilities						414,735		506,792
Principal repayments on credit facilities						(140,958)		(208,101)
Debt issuance costs						(5,957)		(9,847)
Capital lease payments						(77,786)		(40,694)
Employee Stock Ownership Plan						(1,484)		$ (124)
Securitization deposits						298
Common stock dividends paid						$ (19,594)
Investment contract deposits
Investment contract withdrawals
Net cash provided by (used in) financing activities						$ 169,254		$ 248,026
Effects of exchange rate on cash						(12,543)		(3,761)
Increase (decrease) in cash and cash equivalents						509,525		368,692
Cash and cash equivalents at the beginning of period						431,873		464,710
Cash and cash equivalents at the end of the period		$ 941,398		$ 833,402		941,398		833,402
Operating Segments [Member] | Property and Casualty Insurance [Member]
Cash flow from operating activities:
Net earnings		$ 3,942	[1]	$ 4,531	[2]	$ 8,153	[3]	$ 7,145	[4]
Earnings from consolidated entities							[3]		[4]
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation							[3]		[4]
Amortization of deferred policy acquisition costs			[1]		[2]		[5]		[6]
Change in allowance for losses on trade receivables							[3]		[4]
Change in allowance for inventory reserves							[3]		[4]
Net gain on sale of real and personal property							[3]		[4]
Net (gain) loss on sale of investments						$ (810)	[3]	$ (870)	[4]
Deferred income tax						3,127	[3]	2,556	[4]
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables						$ 8,827	[3]	$ 16,061	[4]
Inventories							[3]		[4]
Prepaid expenses							[3]		[4]
Capitalization of deferred policy acquisition costs							[3]		[4]
Other assets						$ 1,097	[3]	$ 802	[4]
Related party assets						(606)	[3]	(1,395)	[4]
Accounts payable and accrued expenses						1,243	[3]	200	[4]
Policy benefits and losses, claims and loss expenses payable						(13,336)	[3]	(17,946)	[4]
Other policyholders' funds and liabilities						$ (1,308)	[3]	$ 205	[4]
Deferred income							[3]		[4]
Related party liabilities						$ (75)	[3]	$ 179	[4]
Net cash provided by operating activities						$ 6,312	[3]	$ 6,937	[4]
Cash flow from investing activities:
Property, plant and equipment							[3]		[4]
Short term investments						$ (19,247)	[3]	$ (32,488)	[4]
Fixed maturities investments						$ (20,286)	[3]	(27,323)	[4]
Equity securities							[3]	(3,281)	[4]
Preferred stock						$ (3)	[3]	(3)	[4]
Real estate						$ (6)	[3]	(3,812)	[4]
Mortgage loans							[3]	$ (3,150)	[4]
Proceeds from sale of:
Property, plant and equipment							[3]		[4]
Short term investments						$ 20,865	[3]	$ 36,003	[4]
Fixed maturities investments						$ 12,783	[3]	15,928	[4]
Equity securities							[3]	$ 3,030	[4]
Preferred stock	[4]
Real estate	[4]							$ 5
Mortgage loans						$ 4,253	[3]	3,760	[4]
Net cash used by investing activities						$ (1,641)	[3]	$ (11,331)	[4]
Cash flow from financing activities:
Borrowings from credit facilities							[3]		[4]
Principal repayments on credit facilities							[3]		[4]
Debt issuance costs									[4]
Capital lease payments							[3]		[4]
Employee Stock Ownership Plan							[3]		[4]
Securitization deposits	[3]
Common stock dividends paid	[3]
Investment contract deposits							[3]		[4]
Investment contract withdrawals							[3]		[4]
Net cash provided by (used in) financing activities							[3]		[4]
Effects of exchange rate on cash							[3]		[4]
Increase (decrease) in cash and cash equivalents						$ 4,671	[3]	$ (4,394)	[4]
Cash and cash equivalents at the beginning of period						8,495	[7]	12,758	[4]
Cash and cash equivalents at the end of the period		$ 13,166	[8]	$ 8,364	[4]	13,166	[8]	8,364	[4]
Operating Segments [Member] | Life Insurance [Member]
Cash flow from operating activities:
Net earnings		5,237	[1]	5,550	[2]	$ 7,976	[3]	$ 8,530	[4]
Earnings from consolidated entities							[3]		[4]
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation							[3]		[4]
Amortization of deferred policy acquisition costs		5,643	[1]	4,290	[2]	$ 10,421	[5]	$ 8,474	[6]
Change in allowance for losses on trade receivables						$ 12	[3]	$ (10)	[4]
Change in allowance for inventory reserves							[3]		[4]
Net gain on sale of real and personal property							[3]		[4]
Net (gain) loss on sale of investments						$ (2,212)	[3]	$ (1,918)	[4]
Deferred income tax						1,007	[3]	1,784	[4]
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables						$ 3,770	[3]	$ (1,060)	[4]
Inventories							[3]		[4]
Prepaid expenses							[3]		[4]
Capitalization of deferred policy acquisition costs						$ (15,636)	[3]	$ (13,728)	[4]
Other assets						$ 88	[3]	$ (858)	[4]
Related party assets							[3]		[4]
Accounts payable and accrued expenses						$ 6,942	[3]	$ 5,902	[4]
Policy benefits and losses, claims and loss expenses payable						4,390	[3]	5,787	[4]
Other policyholders' funds and liabilities						$ 3,992	[3]	$ 951	[4]
Deferred income							[3]		[4]
Related party liabilities						$ 4	[3]	$ (40)	[4]
Net cash provided by operating activities						$ 20,754	[3]	$ 13,814	[4]
Cash flow from investing activities:
Property, plant and equipment							[3]		[4]
Short term investments						$ (229,835)	[3]	$ (97,806)	[4]
Fixed maturities investments						(149,613)	[3]	(86,789)	[4]
Equity securities						$ (1,315)	[3]	$ (426)	[4]
Preferred stock							[3]		[4]
Real estate						$ (17)	[3]	$ (7,500)	[4]
Mortgage loans						$ (74,613)	[3]	$ (12,574)	[4]
Proceeds from sale of:
Property, plant and equipment							[3]		[4]
Short term investments						$ 222,769	[3]	$ 94,323	[4]
Fixed maturities investments						76,302	[3]	$ 33,027	[4]
Equity securities						808	[3]		[4]
Preferred stock	[4]							$ 1,000
Real estate	[4]							396
Mortgage loans						15,631	[3]	4,775	[4]
Net cash used by investing activities						(139,883)	[3]	$ (71,574)	[4]
Cash flow from financing activities:
Borrowings from credit facilities						47,000	[3]		[4]
Principal repayments on credit facilities						$ (47,000)	[3]		[4]
Debt issuance costs									[4]
Capital lease payments							[3]		[4]
Employee Stock Ownership Plan							[3]		[4]
Securitization deposits	[3]
Common stock dividends paid	[3]
Investment contract deposits						$ 150,704	[3]	$ 71,571	[4]
Investment contract withdrawals						(25,974)	[3]	(24,075)	[4]
Net cash provided by (used in) financing activities						$ 124,730	[3]	$ 47,496	[4]
Effects of exchange rate on cash							[3]		[4]
Increase (decrease) in cash and cash equivalents						$ 5,601	[3]	$ (10,264)	[4]
Cash and cash equivalents at the beginning of period						1,482	[7]	17,644	[4]
Cash and cash equivalents at the end of the period		7,083	[8]	7,380	[4]	7,083	[8]	7,380	[4]
Consolidation, Eliminations [Member]
Cash flow from operating activities:
Net earnings		$ (9,179)		$ (10,081)		(16,129)		(15,675)
Earnings from consolidated entities						$ 16,129		$ 15,675
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation
Amortization of deferred policy acquisition costs
Change in allowance for losses on trade receivables
Change in allowance for inventory reserves
Net gain on sale of real and personal property
Net (gain) loss on sale of investments
Deferred income tax
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables
Inventories
Prepaid expenses
Capitalization of deferred policy acquisition costs
Other assets
Related party assets								$ 393	[9]
Accounts payable and accrued expenses
Policy benefits and losses, claims and loss expenses payable
Other policyholders' funds and liabilities
Deferred income
Related party liabilities								$ (393)	[9]
Net cash provided by operating activities
Cash flow from investing activities:
Property, plant and equipment
Short term investments
Fixed maturities investments
Equity securities
Preferred stock
Real estate
Mortgage loans
Proceeds from sale of:
Property, plant and equipment
Short term investments
Fixed maturities investments
Equity securities
Preferred stock
Real estate
Mortgage loans
Net cash used by investing activities
Cash flow from financing activities:
Borrowings from credit facilities
Principal repayments on credit facilities
Debt issuance costs
Capital lease payments
Employee Stock Ownership Plan
Securitization deposits
Common stock dividends paid
Investment contract deposits
Investment contract withdrawals
Net cash provided by (used in) financing activities
Effects of exchange rate on cash
Increase (decrease) in cash and cash equivalents
Cash and cash equivalents at the beginning of period
Cash and cash equivalents at the end of the period

[1] Balances for the quarter ended June 30, 2015

[2] Balances for the quarter ended June 30, 2014

[3] Balance for the period ended June 30, 2015

[4] Balance for the period ended June 30, 2014

[5] Balances for the six months ended June 30, 2015

[6] Balances for the six months ended June 30, 2014

[7] Balances as of December 31, 2014

[8] Balances as of June 30, 2015

[9] Elimination of intercompany investments