Income Tax Expense (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($) Partnership	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) Partnership
Income Tax Expense [Abstract]
Number of investments in partnerships | Partnership	4		4
Investment amount in partnerships	$ 660,000		$ 700,000
Investment Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Investment tax credits	$ 811,000
Tax credits recognition period	5 years 9 months
Tax credits recognized as reduction of tax expense amount	$ 35,000	$ 50,000
Amortization of investment in other expenses	$ 40,000	$ 65,000