Commitments and Contingencies Future Obligations (Details) (USD $)	3 Months Ended			1 Months Ended	3 Months Ended
	Mar. 31, 2014 property	Mar. 31, 2013 property	Dec. 31, 2013	May 07, 2014 Subsequent Event [Member] property	Mar. 31, 2014 Purchase Commitment [Member] Private Capital Management property agreement	Nov. 08, 2013 Series C Cumulative Preferred Stock [Member]	Nov. 08, 2013 Series B Cumulative Preferred [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Redeemable preferred stock percentage						7.25%	8.375%
October 1, 2013 - December 31, 2013	$ 10,264,000
2015	12,922,000
2016	11,575,000
2017	10,248,000
2018	7,918,000
Thereafter	83,734,000
Total	136,661,000
Number of purchase and sale agreements					41
Business acquisition, percentage of voting interests acquired					100.00%
Number of properties acquired	215	112		25	157
Business combination, consideration transferred					520,700,000
Escrow deposit	$ 19,154,000		$ 101,814,000		$ 10,100,000