Investment Securities (Details) (USD $)	3 Months Ended
Mar. 31, 2013	Dec. 31, 2012
Investment Securities
Available for sale securities, Amortized cost	$ 99,438,000	$ 103,860,000
Available for sale securities, Unrealized gains	5,742,000	3,998,000
Available for sale securities, Unrealized losses	(50,000)	(1,093,000)
Available for sale securities, Fair value	105,130,000	106,765,000
Trading securities
Trading securities, Fair value	70,478,000	69,377,000
Investment securities	175,608,000	176,142,000
Purchases of trading securities	49,800,000
Sales of trading securities	50,800,000
Mortgage-backed securities
Investment Securities
Available for sale securities, Amortized cost	9,000	9,000
Available for sale securities, Unrealized gains	1,000	1,000
Available for sale securities, Fair value	10,000	10,000
Trading securities
Trading securities, Fair value	42,000	44,000
Municipal bonds
Trading securities
Trading securities, Fair value	501,000	501,000
Corporate bonds
Investment Securities
Available for sale securities, Amortized cost	30,190,000	30,408,000
Available for sale securities, Unrealized gains	208,000	248,000
Available for sale securities, Unrealized losses	(1,000)	(3,000)
Available for sale securities, Fair value	30,397,000	30,653,000
Trading securities
Trading securities, Fair value	12,049,000	12,112,000
Common Stock
Trading securities
Trading securities, Fair value	48,000	37,000
Affiliated mutual funds
Investment Securities
Available for sale securities, Amortized cost	69,239,000	73,443,000
Available for sale securities, Unrealized gains	5,533,000	3,749,000
Available for sale securities, Unrealized losses	(49,000)	(1,090,000)
Available for sale securities, Fair value	74,723,000	76,102,000
Trading securities
Trading securities, Fair value	$ 57,838,000	$ 56,683,000

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 7

-Footnote 2

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 19

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

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-Publisher FASB

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594

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This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Accounting Standards Codification

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Total debt and equity financial instruments including: (1) securities held-to-maturity, (2) trading securities, and (3) securities available-for-sale which are intended to be held for less than one year or the normal operating cycle, whichever is longer.

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 2

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The cash outflow to acquire securities classified as trading securities and held for investment purposes. Excludes payments for trading securities purchased and held principally for the purpose of selling them in the near term (thus held for only a short period of time).

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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