Fair Value Measurements (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	$ 138,314,000	$ 172,992,000
U.S. Government agency debt obligations [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	79,098,000	88,596,000
Mortgage-backed securities [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	21,996,000	34,610,000
Michigan Strategic Fund bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	11,255,000	16,700,000
Municipal general obligation bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	22,743,000	27,309,000
Mutual funds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	1,405,000	1,354,000
Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis
Assets and liabilities measured at fair value on recurring basis	137,205,000	173,249,000
Fair Value, Measurements, Recurring [Member] \| U.S. Government agency debt obligations [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	79,098,000	88,596,000
Fair Value, Measurements, Recurring [Member] \| Mortgage-backed securities [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	21,996,000	34,610,000
Fair Value, Measurements, Recurring [Member] \| Michigan Strategic Fund bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	11,255,000	16,700,000
Fair Value, Measurements, Recurring [Member] \| Municipal general obligation bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	22,743,000	27,309,000
Fair Value, Measurements, Recurring [Member] \| Municipal revenue bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	1,817,000	4,423,000
Fair Value, Measurements, Recurring [Member] \| Mutual funds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	1,405,000	1,354,000
Fair Value, Measurements, Recurring [Member] \| Interest rate swap agreement [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives	(1,113,000)
Fair Value, Measurements, Recurring [Member] \| Interest rate cap contracts [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives	4,000	257,000
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis
Assets and liabilities measured at fair value on recurring basis	0	0
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| U.S. Government agency debt obligations [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Mortgage-backed securities [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Michigan Strategic Fund bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Municipal general obligation bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Municipal revenue bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Mutual funds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Interest rate swap agreement [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives	0
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Interest rate cap contracts [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives	0	0
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis
Assets and liabilities measured at fair value on recurring basis	137,205,000	173,249,000
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| U.S. Government agency debt obligations [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	79,098,000	88,596,000
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Mortgage-backed securities [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	21,996,000	34,610,000
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Michigan Strategic Fund bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	11,255,000	16,700,000
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Municipal general obligation bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	22,743,000	27,309,000
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Municipal revenue bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	1,817,000	4,423,000
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Mutual funds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	1,405,000	1,354,000
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Interest rate swap agreement [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives	(1,113,000)
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Interest rate cap contracts [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives	4,000	257,000
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis
Assets and liabilities measured at fair value on recurring basis	0	0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| U.S. Government agency debt obligations [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Mortgage-backed securities [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Michigan Strategic Fund bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Municipal general obligation bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Municipal revenue bonds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Mutual funds [Member]
Assets and liabilities measured at fair value on a recurring basis
Available for sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Interest rate swap agreement [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives	0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Interest rate cap contracts [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives	$ 0	$ 0

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

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- Definition

Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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