Incentive Plans (Details Textual) (USD $) Share data in Millions, unless otherwise specified	3 Months Ended				3 Months Ended		12 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Apr. 30, 2014 Subsequent Event [Member]	Mar. 31, 2014 Restricted Stock [Member]	Mar. 31, 2013 Restricted Stock [Member]	Dec. 31, 2013 Restricted Stock [Member]	Mar. 31, 2013 Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	2.5
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	0.3		0.3	5.3
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized					$ 6,000,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition					1 year
Allocated Share-based Compensation Expense	700,000					400,000		200,000
Amortization of restricted stock awards and operating partnership units	677,000	100,000			400,000		100,000
Stock Granted, Value, Share-based Compensation, Net of Forfeitures, Total					$ 100,000	$ 100,000