Fair Value (Estimated Fair Value of Financial Instruments) (Details) (Fair Value, Measurements, Recurring [Member], Interest Rate Swap [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Sep. 30, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	$ 2,753	$ 3,119
Accrued liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	1,751	1,705
Other long-term liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	1,002	1,414
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	2,753	3,119
Carrying Amount [Member] | Accrued liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	1,751	1,705
Carrying Amount [Member] | Other long-term liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	1,002	1,414
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	0	0
Level 1 [Member] | Accrued liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	0	0
Level 1 [Member] | Other long-term liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	2,753	3,119
Level 2 [Member] | Accrued liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	1,751	1,705
Level 2 [Member] | Other long-term liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	1,002	1,414
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	0	0
Level 3 [Member] | Accrued liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	0	0
Level 3 [Member] | Other long-term liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	$ 0	$ 0