SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION BS (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$ 204,341	$ 215,623	$ 261,550	$ 116,361
Accounts receivable	297,443	262,781
Inventories	137,463	153,969
Assets held for sale	29,276	8,290
Prepaid expenses and other current assets	53,084	35,095
Total current assets	721,607	675,758
Intercompany investment	0	0
Investment in unconsolidated affiliates	262,615	272,123
Intercompany notes receivable	0	0
Total property and equipment, at cost	2,792,123	2,414,647
Less - Accumulated depreciation and amortization	(523,372)	(493,575)
Total property and equipment, net	2,268,751	1,921,072
Goodwill	56,680	28,897	29,644
Other assets	88,604	52,842
Total assets	3,398,257	2,950,692
Accounts payable	89,818	69,821
Accrued liabilities	204,498	147,681
Current deferred taxes	12,372	0
Short-term borrowings and current maturities of long-term debt	14,207	22,323
Deferred sale leaseback advance - current	136,930	0
Total current liabilities	457,825	239,825
Long-term debt, less current maturities	827,095	764,946
Intercompany notes payable	0	0
Accrued pension liabilities	86,823	126,647
Other liabilities and deferred credits	78,126	57,196
Deferred taxes	169,519	151,121
Temporary Equity	22,283	0
Common stock	373	367
Additional paid-in capital	762,813	731,883
Retained earnings	1,245,220	1,094,803
Accumulated other comprehensive income (loss)	(156,506)	(199,683)	(159,239)	(130,117)
Treasury shares	(103,965)	(26,304)
Stockholders' equity	1,747,935	1,601,066
Noncontrolling interests	8,651	9,891
Total stockholders' investment	1,756,586	1,610,957	1,521,824	1,518,775
Total liabilities and stockholders' investment	3,398,257	2,950,692
Land and Building [Member]
Condensed Financial Statements, Captions [Line Items]
Total property and equipment, at cost	145,973	108,593
Aircraft and equipment [Member]
Condensed Financial Statements, Captions [Line Items]
Total property and equipment, at cost	2,646,150	2,306,054
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	4,640	31,853	76,609	24,075
Accounts receivable	32,280	18,498
Inventories	0	0
Assets held for sale	0	0
Prepaid expenses and other current assets	3,882	16,071
Total current assets	40,802	66,422
Intercompany investment	1,273,337	1,163,935
Investment in unconsolidated affiliates	0	0
Intercompany notes receivable	1,286,354	1,401,680
Total property and equipment, at cost	65,071	32,249
Less - Accumulated depreciation and amortization	(13,057)	(10,680)
Total property and equipment, net	52,014	21,569
Goodwill	0	0
Other assets	204,679	40,877
Total assets	2,857,186	2,694,483
Accounts payable	8,298	4,049
Accrued liabilities	36,442	29,534
Current deferred taxes	(7,640)	(4,184)
Short-term borrowings and current maturities of long-term debt	4,543	21,875
Deferred sale leaseback advance - current	0
Total current liabilities	41,643	51,274
Long-term debt, less current maturities	805,965	764,946
Intercompany notes payable	0	0
Accrued pension liabilities	0	0
Other liabilities and deferred credits	13,750	10,761
Deferred taxes	144,461	128,153
Temporary Equity	0
Common stock	373	367
Additional paid-in capital	762,813	731,883
Retained earnings	1,245,220	1,094,803
Accumulated other comprehensive income (loss)	(54,719)	(62,892)
Treasury shares	(103,965)	(26,304)
Stockholders' equity	1,849,722	1,737,857
Noncontrolling interests	1,645	1,492
Total stockholders' investment	1,851,367	1,739,349
Total liabilities and stockholders' investment	2,857,186	2,694,483
Parent Company [Member] | Land and Building [Member]
Condensed Financial Statements, Captions [Line Items]
Total property and equipment, at cost	977	939
Parent Company [Member] | Aircraft and equipment [Member]
Condensed Financial Statements, Captions [Line Items]
Total property and equipment, at cost	64,094	31,310
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0	5,370	3,155	5,233
Accounts receivable	104,155	80,615
Inventories	40,864	51,970
Assets held for sale	8,505	1,268
Prepaid expenses and other current assets	3,258	12,415
Total current assets	156,782	151,638
Intercompany investment	111,435	111,435
Investment in unconsolidated affiliates	0	150
Intercompany notes receivable	0	0
Total property and equipment, at cost	1,406,625	1,219,438
Less - Accumulated depreciation and amortization	(211,385)	(205,746)
Total property and equipment, net	1,195,240	1,013,692
Goodwill	4,755	4,756
Other assets	1,462	1,341
Total assets	1,469,674	1,283,012
Accounts payable	67,728	44,017
Accrued liabilities	32,084	22,404
Current deferred taxes	(1,342)	115
Short-term borrowings and current maturities of long-term debt	0	0
Deferred sale leaseback advance - current	136,930
Total current liabilities	235,400	66,536
Long-term debt, less current maturities	0	0
Intercompany notes payable	378,983	463,184
Accrued pension liabilities	0	0
Other liabilities and deferred credits	37,876	8,530
Deferred taxes	9,472	8,328
Temporary Equity	0
Common stock	4,996	4,996
Additional paid-in capital	9,291	9,291
Retained earnings	793,656	722,147
Accumulated other comprehensive income (loss)	0	0
Treasury shares	0	0
Stockholders' equity	807,943	736,434
Noncontrolling interests	0	0
Total stockholders' investment	807,943	736,434
Total liabilities and stockholders' investment	1,469,674	1,283,012
Guarantor Subsidiaries [Member] | Land and Building [Member]
Condensed Financial Statements, Captions [Line Items]
Total property and equipment, at cost	49,499	48,907
Guarantor Subsidiaries [Member] | Aircraft and equipment [Member]
Condensed Financial Statements, Captions [Line Items]
Total property and equipment, at cost	1,357,126	1,170,531
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	200,147	178,400	181,786	87,053
Accounts receivable	310,288	246,612
Inventories	96,599	101,999
Assets held for sale	20,771	7,022
Prepaid expenses and other current assets	45,944	23,263
Total current assets	673,749	557,296
Intercompany investment	0	0
Investment in unconsolidated affiliates	262,615	271,973
Intercompany notes receivable	0	0
Total property and equipment, at cost	1,320,427	1,162,960
Less - Accumulated depreciation and amortization	(298,930)	(277,149)
Total property and equipment, net	1,021,497	885,811
Goodwill	51,925	24,141
Other assets	50,392	149,544
Total assets	2,060,178	1,888,765
Accounts payable	157,297	101,021
Accrued liabilities	141,423	115,112
Current deferred taxes	21,354	4,069
Short-term borrowings and current maturities of long-term debt	9,664	448
Deferred sale leaseback advance - current	0
Total current liabilities	329,738	220,650
Long-term debt, less current maturities	21,130	0
Intercompany notes payable	1,076,292	963,687
Accrued pension liabilities	86,823	126,647
Other liabilities and deferred credits	26,500	178,525
Deferred taxes	15,586	14,640
Temporary Equity	22,283
Common stock	22,876	22,876
Additional paid-in capital	270,905	270,905
Retained earnings	177,159	62,602
Accumulated other comprehensive income (loss)	3,880	19,834
Treasury shares	0	0
Stockholders' equity	474,820	376,217
Noncontrolling interests	7,006	8,399
Total stockholders' investment	481,826	384,616
Total liabilities and stockholders' investment	2,060,178	1,888,765
Non-Guarantor Subsidiaries [Member] | Land and Building [Member]
Condensed Financial Statements, Captions [Line Items]
Total property and equipment, at cost	95,497	58,747
Non-Guarantor Subsidiaries [Member] | Aircraft and equipment [Member]
Condensed Financial Statements, Captions [Line Items]
Total property and equipment, at cost	1,224,930	1,104,213
Consolidations, Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	(446)	0	0	0
Accounts receivable	(149,280)	(82,944)
Inventories	0	0
Assets held for sale	0	0
Prepaid expenses and other current assets	0	(16,654)
Total current assets	(149,726)	(99,598)
Intercompany investment	(1,384,772)	(1,275,370)
Investment in unconsolidated affiliates	0	0
Intercompany notes receivable	(1,286,354)	(1,401,680)
Total property and equipment, at cost	0	0
Less - Accumulated depreciation and amortization	0	0
Total property and equipment, net	0	0
Goodwill	0	0
Other assets	(167,929)	(138,920)
Total assets	(2,988,781)	(2,915,568)
Accounts payable	(143,505)	(79,266)
Accrued liabilities	(5,451)	(19,369)
Current deferred taxes	0	0
Short-term borrowings and current maturities of long-term debt	0	0
Deferred sale leaseback advance - current	0
Total current liabilities	(148,956)	(98,635)
Long-term debt, less current maturities	0	0
Intercompany notes payable	(1,455,275)	(1,426,871)
Accrued pension liabilities	0	0
Other liabilities and deferred credits	0	(140,620)
Deferred taxes	0	0
Temporary Equity	0
Common stock	(27,872)	(27,872)
Additional paid-in capital	(280,196)	(280,196)
Retained earnings	(970,815)	(784,749)
Accumulated other comprehensive income (loss)	(105,667)	(156,625)
Treasury shares	0	0
Stockholders' equity	(1,384,550)	(1,249,442)
Noncontrolling interests	0	0
Total stockholders' investment	(1,384,550)	(1,249,442)
Total liabilities and stockholders' investment	(2,988,781)	(2,915,568)
Consolidations, Eliminations [Member] | Land and Building [Member]
Condensed Financial Statements, Captions [Line Items]
Total property and equipment, at cost	0	0
Consolidations, Eliminations [Member] | Aircraft and equipment [Member]
Condensed Financial Statements, Captions [Line Items]
Total property and equipment, at cost	$ 0	$ 0