Condensed Consolidating Statement of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2012	Nov. 30, 2011
Cash flows from operating activities:
Net earnings (loss)	$ 12,561	$ 13,328
Adjustments to reconcile net earnings (loss) to net cash provided by (used in) operating activities:
Deferred income taxes	940	3,665
Depreciation and amortization	10,923	9,889
Gain on sales of leased equipment	(1,408)	(3,658)
Accretion of debt discount	849	787
Stock based compensation	1,886	1,742
Other	(1,705)	2,024
Decrease (increase) in assets
Accounts receivable	(15,515)	33,687
Inventories	(41,465)	(34,088)
Leased railcars for syndication	43,501	(37,339)
Other	945	856
Increase (decrease) in liabilities
Accounts payable and accrued liabilities	(48,036)	260
Deferred revenue	11,039	(145)
Net cash provided by (used in) operating activities	(25,485)	(8,992)
Cash flows from investing activities:
Proceeds from sales of equipment	10,086	5,741
Investment in and net advances to unconsolidated affiliates	(160)	70
Decrease (increase) in restricted cash	(1,045)	(38)
Capital expenditures	(25,141)	(15,007)
Other		10
Net cash provided by (used in) investing activities	(16,260)	(9,224)
Cash flows from financing activities:
Net change in revolving notes with maturities of 90 days or less	27,935	(9,150)
Proceeds from revolving notes with maturities longer than 90 days	9,195	7,557
Repayment of revolving notes with maturities longer than 90 days	(8,941)	(5,606)
Proceeds from notes payable		2,500
Repayments of notes payable	(1,230)	(1,243)
Other
Investment by joint venture partner	1,182
Excess tax benefit from restricted stock awards	217
Net cash provided by (used in) financing activities	28,358	(5,942)
Effect of exchange rate changes	1,100	(5,209)
Decrease in cash and cash equivalents	(12,287)	(29,367)
Beginning of period	53,571	50,222
End of period	41,284	20,855
Parent
Cash flows from operating activities:
Net earnings (loss)	10,427	14,517
Adjustments to reconcile net earnings (loss) to net cash provided by (used in) operating activities:
Deferred income taxes	2,481	4,416
Depreciation and amortization	576	699
Accretion of debt discount	849	787
Stock based compensation	1,886	1,742
Decrease (increase) in assets
Accounts receivable	915	13,596
Other	212	853
Increase (decrease) in liabilities
Accounts payable and accrued liabilities	(27,865)	(24,758)
Deferred revenue	(39)	(39)
Net cash provided by (used in) operating activities	(10,558)	11,813
Cash flows from investing activities:
Investment in and net advances to unconsolidated affiliates	(20,413)	(22,433)
Intercompany advances	4	(2,632)
Capital expenditures	(49)	(311)
Net cash provided by (used in) investing activities	(20,458)	(25,376)
Cash flows from financing activities:
Net change in revolving notes with maturities of 90 days or less	41,750	(8,000)
Intercompany advances	(11,688)	1,713
Other
Excess tax benefit from restricted stock awards	217
Net cash provided by (used in) financing activities	30,279	(6,287)
Decrease in cash and cash equivalents	(737)	(19,850)
Beginning of period	34,323	33,368
End of period	33,586	13,518
Combined Guarantor Subsidiaries
Cash flows from operating activities:
Net earnings (loss)	13,830	21,397
Adjustments to reconcile net earnings (loss) to net cash provided by (used in) operating activities:
Deferred income taxes	(1,656)	(737)
Depreciation and amortization	7,922	7,404
Gain on sales of leased equipment	(1,044)	(3,657)
Other	98	603
Decrease (increase) in assets
Accounts receivable	(18,193)	(18,628)
Inventories	(39,095)	14,918
Leased railcars for syndication	45,243	(38,759)
Other	(141)	1,049
Increase (decrease) in liabilities
Accounts payable and accrued liabilities	(24,450)	27,610
Deferred revenue	11,506	(145)
Net cash provided by (used in) operating activities	(5,980)	11,055
Cash flows from investing activities:
Proceeds from sales of equipment	10,086	5,741
Investment in and net advances to unconsolidated affiliates	(85)	683
Decrease (increase) in restricted cash	57	(38)
Capital expenditures	(16,676)	(12,625)
Other		10
Net cash provided by (used in) investing activities	(6,618)	(6,229)
Cash flows from financing activities:
Intercompany advances	12,944	(4,006)
Repayments of notes payable	(1,028)	(1,041)
Other
Net cash provided by (used in) financing activities	11,916	(5,047)
Effect of exchange rate changes	402	(76)
Decrease in cash and cash equivalents	(280)	(297)
Beginning of period	294	529
End of period	14	232
Combined Non-Guarantor Subsidiaries
Cash flows from operating activities:
Net earnings (loss)	3,243	1,403
Adjustments to reconcile net earnings (loss) to net cash provided by (used in) operating activities:
Deferred income taxes	(736)	488
Depreciation and amortization	2,448	1,803
Other	1	1
Decrease (increase) in assets
Accounts receivable	1,676	38,699
Inventories	(2,384)	(48,856)
Other	3,318	(1,046)
Increase (decrease) in liabilities
Accounts payable and accrued liabilities	4,277	(2,571)
Deferred revenue	(430)	39
Net cash provided by (used in) operating activities	11,413	(10,040)
Cash flows from investing activities:
Investment in and net advances to unconsolidated affiliates	(160)
Decrease (increase) in restricted cash	(1,102)
Capital expenditures	(8,278)	(2,071)
Net cash provided by (used in) investing activities	(9,540)	(2,071)
Cash flows from financing activities:
Net change in revolving notes with maturities of 90 days or less	(13,815)	(1,150)
Proceeds from revolving notes with maturities longer than 90 days	9,195	7,557
Repayment of revolving notes with maturities longer than 90 days	(8,941)	(5,606)
Intercompany advances	(1,260)	4,925
Proceeds from notes payable		2,500
Repayments of notes payable	(202)	(202)
Other
Investment by joint venture partner	1,182
Net cash provided by (used in) financing activities	(13,841)	8,024
Effect of exchange rate changes	698	(5,133)
Decrease in cash and cash equivalents	(11,270)	(9,220)
Beginning of period	18,954	16,325
End of period	7,684	7,105
Eliminations
Cash flows from operating activities:
Net earnings (loss)	(14,939)	(23,989)
Adjustments to reconcile net earnings (loss) to net cash provided by (used in) operating activities:
Deferred income taxes	851	(502)
Depreciation and amortization	(23)	(17)
Gain on sales of leased equipment	(364)	(1)
Other	(1,804)	1,420
Decrease (increase) in assets
Accounts receivable	87	20
Inventories	14	(150)
Leased railcars for syndication	(1,742)	1,420
Other	(2,444)
Increase (decrease) in liabilities
Accounts payable and accrued liabilities	2	(21)
Deferred revenue	2
Net cash provided by (used in) operating activities	(20,360)	(21,820)
Cash flows from investing activities:
Investment in and net advances to unconsolidated affiliates	20,498	21,820
Intercompany advances	(4)	2,632
Capital expenditures	(138)
Net cash provided by (used in) investing activities	20,356	24,452
Cash flows from financing activities:
Intercompany advances	4	(2,632)
Other
Net cash provided by (used in) financing activities	$ 4	$ (2,632)