Real Estate Investments - Narrative (Details) (USD $)	3 Months Ended			3 Months Ended			3 Months Ended		1 Months Ended		0 Months Ended		1 Months Ended	0 Months Ended	3 Months Ended
	Mar. 31, 2014 Property ConstructionLoan	Mar. 31, 2013	Dec. 31, 2013 Property	Mar. 31, 2014 Discontinued Operations [Member]	Mar. 31, 2013 Discontinued Operations [Member]	Dec. 31, 2013 Discontinued Operations [Member]	Mar. 31, 2014 Other Mortgage Loans [Member] Other Property [Member] IOWA	Mar. 31, 2014 Construction Loans [Member] Medical Office Building [Member] OKLAHOMA	Apr. 30, 2014 Subsequent Event TEXAS	Mar. 31, 2014 Subsequent Event TEXAS	Apr. 11, 2014 Real Estate Dispositions [Member] FLORIDA Medical Building Disposed April 11 2014 [Member]	Apr. 23, 2014 Real Estate Dispositions [Member] Subsequent Event TEXAS Medical Building Disposed April 23 2014 [Member]	Mar. 31, 2014 Real Estate Dispositions [Member] Subsequent Event TEXAS Medical Building Disposed April 23 2014 [Member]	Apr. 11, 2014 Real Estate Dispositions [Member] Subsequent Event FLORIDA Medical Building Disposed April 11 2014 [Member]	Mar. 31, 2014 Transferred to Held For Sale [Member] Discontinued Operations [Member]	Mar. 31, 2014 Designated For Sale [Member] Discontinued Operations [Member]
Acquisitions and Dispositions [Line Items]
Real Estate Investment Net Disposed of During Period												$ 4,100,000		$ 1,700,000
Face amount of mortgages							40,000,000
Stated interest rate, percent							7.70%
Additional points for default rate, percent							3.00%
Exit fee							1,500,000
Disposition Sales Price												4,400,000		1,800,000
Proceeds from Sale of Real Estate Held-for-investment												4,200,000		1,700,000
Closing Adjustments Disposed Entity												200,000		100,000
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property											2,400,000		2,600,000	900,000
Noncontrolling interest, ownership percentage by parent									40.00%
Purchase of Noncontrolling Interests									8,200,000
Noncontrolling interests	1,605,000		1,809,000							1,605,000
Existing Construction Mortgage Loans Funded	800,000
Number of Mortgage Notes Receivable Outstanding	1
Mortgage notes receivable	86,372,000	125,547,000	125,547,000					80,800,000
Anticipated Amount of Investment								14,100,000
Construction Budget Approximately								10,400,000
Number of Properties Reclassified to Held For Sale	1
Real estate properties, Total	3,106,447,000		3,067,187,000	24,571,000		16,978,000									8,500,000
Total real estate properties, net	2,454,098,000		2,435,078,000	9,957,000		6,767,000									4,100,000
Impairments	$ 3,425,000	$ 3,630,000		$ (3,425,000)	$ (3,630,000)										$ (2,600,000)	$ (900,000)
Number of Properties Held for Sale	4		3