SELECTED CONSOLIDATING FINANCIAL STATEMENTS OF PARENT, GUARANTORS AND NON-GUARANTORS (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Current assets:
Cash and cash equivalents	$ 25,415	$ 32,037	$ 33,452	$ 29,662
Trade and other receivables, net	466,393	434,158
Inventories	1,127,758	988,963
Rotable assets	39,567	34,853
Deferred income taxes	48,401	99,546
Prepaid expenses and other	22,555	24,481
Assets Held-for-sale, Current	27,401	14,747
Total current assets	1,757,490	1,628,785
Property and equipment, net	932,067	815,084
Goodwill and other intangible assets, net	2,768,901	2,700,770
Other, net	69,088	66,792
Intercompany investments and advances	0	0
Total assets	5,527,546	5,211,431
Current liabilities:
Current portion of long-term debt	45,355	133,930
Accounts payable	257,908	327,426
Accrued expenses	250,338	280,469
Liabilities of Assets Held-for-sale	4,225	2,621
Total current liabilities	557,826	744,446
Long-term debt, less current portion	1,576,179	1,195,933
Intercompany debt	0	0
Accrued pension and other postretirement benefits, noncurrent	465,204	671,175
Deferred income taxes and other	628,745	554,719
Total stockholders' equity	2,299,592	2,045,158
Total liabilities and stockholders' equity	5,527,546	5,211,431
Parent
Current assets:
Cash and cash equivalents	2,817	3,110	3,410	7,969
Trade and other receivables, net	148	1,141
Inventories	0	0
Rotable assets	0	0
Deferred income taxes	47,985	0
Prepaid expenses and other	11,345	5,533
Assets Held-for-sale, Current	0	0
Total current assets	62,295	9,784
Property and equipment, net	10,494	9,999
Goodwill and other intangible assets, net	0	335
Other, net	58,677	58,526
Intercompany investments and advances	3,620,302	3,137,667
Total assets	3,751,768	3,216,311
Current liabilities:
Current portion of long-term debt	27,956	109,648
Accounts payable	5,505	9,400
Accrued expenses	37,820	35,894
Liabilities of Assets Held-for-sale	0	0
Total current liabilities	71,281	154,942
Long-term debt, less current portion	1,364,274	998,200
Intercompany debt	0	0
Accrued pension and other postretirement benefits, noncurrent	7,376	7,264
Deferred income taxes and other	9,245	10,747
Total stockholders' equity	2,299,592	2,045,158
Total liabilities and stockholders' equity	3,751,768	3,216,311
Guarantors Subsidiaries
Current assets:
Cash and cash equivalents	510	1,537	617	2,237
Trade and other receivables, net	231,404	171,360
Inventories	1,060,072	958,141
Rotable assets	26,014	24,903
Deferred income taxes	0	99,546
Prepaid expenses and other	8,292	16,058
Assets Held-for-sale, Current	27,401	14,747
Total current assets	1,353,693	1,286,292
Property and equipment, net	808,672	753,510
Goodwill and other intangible assets, net	2,612,475	2,654,919
Other, net	7,894	7,873
Intercompany investments and advances	(16,523)	325,786
Total assets	4,766,211	5,028,380
Current liabilities:
Current portion of long-term debt	17,399	24,282
Accounts payable	234,788	309,363
Accrued expenses	201,322	235,061
Liabilities of Assets Held-for-sale	4,225	2,621
Total current liabilities	457,734	571,327
Long-term debt, less current portion	60,104	47,733
Intercompany debt	2,006,955	2,193,874
Accrued pension and other postretirement benefits, noncurrent	457,374	663,911
Deferred income taxes and other	583,892	545,221
Total stockholders' equity	1,200,152	1,006,314
Total liabilities and stockholders' equity	4,766,211	5,028,380
Non-Guarantor Subsidiaries
Current assets:
Cash and cash equivalents	22,088	27,390	29,425	19,456
Trade and other receivables, net	234,841	261,657
Inventories	67,686	30,822
Rotable assets	13,553	9,950
Deferred income taxes	416	0
Prepaid expenses and other	2,918	2,890
Assets Held-for-sale, Current	0	0
Total current assets	341,502	332,709
Property and equipment, net	112,901	51,575
Goodwill and other intangible assets, net	156,426	45,516
Other, net	2,517	393
Intercompany investments and advances	11,281	2,777
Total assets	624,627	432,970
Current liabilities:
Current portion of long-term debt	0	0
Accounts payable	17,615	8,663
Accrued expenses	11,196	9,514
Liabilities of Assets Held-for-sale		0
Total current liabilities	28,811	18,177
Long-term debt, less current portion	151,801	150,000
Intercompany debt	245,355	202,621
Accrued pension and other postretirement benefits, noncurrent	454	0
Deferred income taxes and other	47,892	0
Total stockholders' equity	150,314	62,172
Total liabilities and stockholders' equity	624,627	432,970
Eliminations
Current assets:
Cash and cash equivalents	0	0	0	0
Trade and other receivables, net	0	0
Inventories	0	0
Rotable assets	0	0
Deferred income taxes	0	0
Prepaid expenses and other	0	0
Assets Held-for-sale, Current	0	0
Total current assets	0	0
Property and equipment, net	0	0
Goodwill and other intangible assets, net	0	0
Other, net	0	0
Intercompany investments and advances	(3,615,060)	(3,466,230)
Total assets	(3,615,060)	(3,466,230)
Current liabilities:
Current portion of long-term debt	0	0
Accounts payable	0	0
Accrued expenses	0	0
Liabilities of Assets Held-for-sale		0
Total current liabilities	0	0
Long-term debt, less current portion	0	0
Intercompany debt	(2,252,310)	(2,396,495)
Accrued pension and other postretirement benefits, noncurrent	0	0
Deferred income taxes and other	(12,284)	(1,249)
Total stockholders' equity	(1,350,466)	(1,068,486)
Total liabilities and stockholders' equity	$ (3,615,060)	$ (3,466,230)