Debt Obligations - Junior Subordinated Notes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014
Debt Instrument [Line Items]
Total debt obligations	$ 539,503us-gaap_LongTermDebt		519,806us-gaap_LongTermDebt
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Total debt obligations	37,400		37,400
Interest Expense	458	458
Amortization of deferred costs included in interest expense	$ 5	$ 5
Debt Instrument, Interest Rate 30 April, 2016 Through 30 April, 2036 [Member] \| Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis	LIBOR		LIBOR
Debt Instrument, Basis Spread on Variable Rate	2.00%		2.00%
Debt Instrument, Interest Rate 1 August, 2012 Through 29 April, 2016 [Member] \| Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Interest Rate	4.90%		4.90%

Amount of noncash expense included in interest expense to issue debt and obtain financing associated with the related debt instruments. Alternate captions include noncash interest expense.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

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-Number 210

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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