Income per Common Share of the Trust, Dilutive (Details) - shares	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Stock Option [Member] | Common shares [Member]
Stock Option Exercises [Line Items]
Amount of Options Exercises in Period	8,000	53,000	44,000