Subsequent Events (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended				0 Months Ended			1 Months Ended		0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Oct. 22, 2014 Subsequent event	Jul. 02, 2014 Common shares	Apr. 03, 2014 Common shares	Jan. 02, 2014 Common shares	Oct. 31, 2013 Common shares	Jul. 31, 2013 Common shares	Oct. 02, 2014 Common shares Subsequent event
Subsequent Event [Line Items]
Dividends paid per common share	$ 0.225	$ 0.167	$ 0.559	$ 0.292			$ 0.225	$ 0.167	$ 0.167	$ 0.167	$ 0.167	$ 0.225
Investment commitment	$ 479,635		$ 479,635		$ 467,524	$ 225,000