Schedule III - Real Estate and Accumulated Depreciation (Details) (USD $) In Thousands, unless otherwise specified					12 Months Ended
	Dec. 31, 2013 property	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013 Medical office/outpatient [Member] Property		Dec. 31, 2013 Medical office/outpatient [Member] Minimum [Member]	Dec. 31, 2013 Medical office/outpatient [Member] Maximum [Member]	Dec. 31, 2013 Inpatient [Member] Property		Dec. 31, 2013 Inpatient [Member] Minimum [Member]	Dec. 31, 2013 Inpatient [Member] Maximum [Member]	Dec. 31, 2013 Other [Member] Property		Dec. 31, 2013 Other [Member] Minimum [Member]	Dec. 31, 2013 Other [Member] Maximum [Member]	Dec. 31, 2013 Real Estate [Member] Property		Dec. 31, 2013 Land Held for Development [Member] Property		Dec. 31, 2013 Corporate Property [Member] Property		Dec. 31, 2013 Owned Property [Member] Property
Summary of real estate properties
Number of Properties	198				177				14				10				201		0		0		201
State					AL, AZ, CA, CO, DC, FL, GA,  HI, IA, IL, IN,  KS, LA, MD, MI, MO, MS, NC, NV, OH, OR, PA, SC, SD, TN, TX, VA, WA				AZ, CA, CO, IN, MO, PA, TX				AL, IN, MI TN, VA
Land
Initial Investment					$ 152,084				$ 23,237				$ 1,828				$ 177,149		$ 17,054		$ 0		$ 194,203
Cost Capitalized Subsequent to Acquisition					3,137				150				73				3,360		0		0		3,360
Total	195,985				155,221				23,387				1,901				180,509		17,054		0		197,563
Buildings, Improvements, Lease Intangibles and CIP
Initial Investment					2,108,791				404,427				36,323				2,549,541		0		0		2,549,541
Cost Capitalized Subsequent to Acquisition					310,442				9,505				7,848				327,795		0		0		327,795
Total					2,419,233				413,932				44,171				2,877,336		0		0		2,877,336
Personal Property	9,267				2,969				265				636				3,870		0		5,397		9,267
Gross real estate asset, Total	3,084,166	2,830,931	2,831,732	2,605,516	2,577,423	[1],[2]			437,584	[1],[2]			46,708	[1],[2]			3,061,715	[1],[2]	17,054	[1],[2]	5,397	[1],[2]	3,084,166	[1],[2]
Accumulated depreciation	642,320	586,920	536,682	500,406	542,671	[1],[3]			71,563	[1],[3]			24,494	[1],[3]			638,728	[1],[3]	89	[1],[3]	3,503	[1],[3]	642,320	[1],[3]
Encumbrances					$ 164,269	[4]			$ 0	[4]			$ 1,527	[4]			$ 165,796	[4]	$ 0	[4]	$ 0	[4]	$ 165,796	[4]
Date Acquired							Jan. 01, 1993	Dec. 31, 2012			Jan. 01, 1994	Dec. 31, 2012			Jan. 01, 1993	Dec. 31, 2011
Date Constructed							Jan. 01, 1905	Dec. 31, 2012			Jan. 01, 1983	Dec. 31, 2012			Jan. 01, 1906	Dec. 31, 1995

[1] Depreciation is provided for on a straight-line basis on buildings and improvements over 3.3 to 39.0 years, lease intangibles over 2.0 to 93.1 years, personal property over 1.9 to 15.8 years, and land improvements over 15.0 to 38.1 years.

[2] Total assets as of December 31, 2013 have an estimated aggregate total cost of $3.1 billion for federal income tax purposes.

[3] Includes three assets held for sale as of December 31, 2013 of approximately $17.0 million (gross) and accumulated depreciation of $10.2 million, one asset held for sale as of December 31, 2012 of approximately $9.6 million (gross) and accumulated depreciation of $6.3 million; and 15 assets held for sale as of December 31, 2011 of $52.8 million (gross) and accumulated depreciation of $24.6 million.

[4] Includes unaccreted discounts, net of premiums totaling $0.9 million as of December 31, 2013.