Income Tax Expense (Details) (USD $)	3 Months Ended
	Mar. 31, 2015 Partnerships	Dec. 31, 2014
Income Tax Expense [Abstract]
Investments in number of partnerships	4
Investment amount in partnerships	$ 1,153,000	$ 1,218,000
Tax Credit Carryforward [Line Items]
Investment tax credits	1,193,000
Investment Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax credits recognition period	9 years
Tax credits recognized as reduction of tax expense amount	$ 50,000