Revolving Credit Agreement (Details) - Webster Credit Line		6 Months Ended
	Jun. 21, 2016 USD ($)	May 31, 2016 USD ($) ft²
Revolving credit agreement
Maximum borrowing capacity	$ 15,000,000	$ 12,500,000
Extension period	2 years
Proceeds from Lines of Credit		0
Standby letters of credit aggregate amount		$ 4,117,000
Griffin Center South, Bloomfield, CT
Revolving credit agreement
Area of collateralized properties (in square feet) | ft²		235,000
Single-story office building in Griffin Center
Revolving credit agreement
Area of collateralized properties (in square feet) | ft²		48,000
LIBOR
Revolving credit agreement
Variable interest rate margin (as a percent)		2.75%