Investment in Available-for-Sale Securities (Details) (USD $)	3 Months Ended	12 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Cost	$ 1,674,837	$ 1,925,012
Available-for-sale Securities, Gross Unrealized Gains	23,480	23,733
Available-for-sale Securities, Gross Unrealized Losses	(14,837)	(15,944)
Available-for-sale Securities, Fair Value	1,683,480us-gaap_AvailableForSaleSecurities	1,932,801us-gaap_AvailableForSaleSecurities
U.S. federal agency securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Cost	49,761	49,739
Available-for-sale Securities, Gross Unrealized Gains	87	68
Available-for-sale Securities, Gross Unrealized Losses	(29)	(117)
Available-for-sale Securities, Fair Value	49,819	49,690
Municipal securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Cost	273,705	441,372
Available-for-sale Securities, Gross Unrealized Gains	293	463
Available-for-sale Securities, Gross Unrealized Losses	(785)	(966)
Available-for-sale Securities, Fair Value	273,213	440,869
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Cost	1,313,716	1,395,990
Available-for-sale Securities, Gross Unrealized Gains	22,647	22,904
Available-for-sale Securities, Gross Unrealized Losses	(14,023)	(14,861)
Available-for-sale Securities, Fair Value	1,322,340	1,404,033
Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Cost	37,655	37,911
Available-for-sale Securities, Gross Unrealized Gains	453	298
Available-for-sale Securities, Gross Unrealized Losses	0	0
Available-for-sale Securities, Fair Value	$ 38,108	$ 38,209

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

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-Section 50

-Paragraph 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

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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.

+ References

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)

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Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

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-Section 50

-Paragraph 2

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Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

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