Derivative Financial Instruments (Details 2) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Oct. 31, 2011
Derivative assets:
Derivative assets	$ 14,488
Recurring [Member]
Derivative liabilities:
Assets at Fair Value	14,488	(10,344)
Recurring [Member] | Other Receivables [Member]
Derivative liabilities:
Assets at Fair Value	21,566	1,031
Recurring [Member] | Other Assets [Member]
Derivative liabilities:
Assets at Fair Value		1,610
Recurring [Member] | Accrued Liability [Member]
Derivative liabilities:
Assets at Fair Value	(5,774)	(12,297)
Recurring [Member] | Other long-term liabilities [Member]
Derivative liabilities:
Assets at Fair Value	(1,304)	(688)
Recurring [Member] | Level 1 [Member]
Derivative liabilities:
Total fair value
Recurring [Member] | Level 1 [Member] | Other Receivables [Member]
Derivative assets:
Derivative assets
Recurring [Member] | Level 1 [Member] | Other Assets [Member]
Derivative assets:
Derivative assets
Recurring [Member] | Level 1 [Member] | Accrued Liability [Member]
Derivative liabilities:
Derivative liabilities
Recurring [Member] | Level 1 [Member] | Other long-term liabilities [Member]
Derivative liabilities:
Derivative liabilities
Recurring [Member] | Level 2 [Member]
Derivative liabilities:
Total fair value	14,488	(10,344)
Recurring [Member] | Level 2 [Member] | Other Receivables [Member]
Derivative assets:
Derivative assets	21,566	1,031
Recurring [Member] | Level 2 [Member] | Other Assets [Member]
Derivative assets:
Derivative assets		1,610
Recurring [Member] | Level 2 [Member] | Accrued Liability [Member]
Derivative liabilities:
Derivative liabilities	(5,774)	(12,297)
Recurring [Member] | Level 2 [Member] | Other long-term liabilities [Member]
Derivative liabilities:
Derivative liabilities	(1,304)	(688)
Recurring [Member] | Level 3 [Member]
Derivative liabilities:
Total fair value
Recurring [Member] | Level 3 [Member] | Other Receivables [Member]
Derivative assets:
Derivative assets
Recurring [Member] | Level 3 [Member] | Other Assets [Member]
Derivative assets:
Derivative assets
Recurring [Member] | Level 3 [Member] | Accrued Liability [Member]
Derivative liabilities:
Derivative liabilities
Recurring [Member] | Level 3 [Member] | Other long-term liabilities [Member]
Derivative liabilities:
Derivative liabilities