Dividends on Common Stock (Details Textual) - $ / shares	3 Months Ended				6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Jun. 30, 2014
Common Stock, Dividends, Per Share, Cash Paid		$ 0.175		$ 0.15	$ 0.20	$ 0.15
Common Stock, Dividends, Per Share, Declared	$ 0.2	$ 0.175	$ 0.15	$ 0.15	$ 0.375	$ 0.30