Acquisitions of Real Estate Property (Estimated Fair Value) (Details 2) (USD $) In Thousands, unless otherwise specified	1 Months Ended	12 Months Ended
	Aug. 31, 2012	Dec. 31, 2013 2013 Acquisitions	Dec. 31, 2013 2013 Acquisitions Triple Net Leased Properties	Dec. 31, 2013 2013 Acquisitions Senior Living Operations	Dec. 31, 2013 2013 Acquisitions MOB Operations	Dec. 31, 2012 2012 Acquisitions	Dec. 31, 2012 2012 Acquisitions Triple Net Leased Properties	Dec. 31, 2012 2012 Acquisitions Senior Living Operations	Dec. 31, 2012 2012 Acquisitions MOB Operations
Business Combinations
Land and improvements		$ 100,908	$ 51,419	$ 45,566	$ 3,923	$ 195,047	$ 21,881	$ 60,662	$ 112,504
Buildings and improvements		1,521,596	803,227	579,577	138,792	1,724,848	225,950	413,750	1,085,148
Construction in progress						25,579	0	0	25,579
Acquired lease intangibles		36,227	8,945	16,920	10,362	202,799	2,323	18,070	182,406
Other assets		8,345	3,285	2,607	2,453	46,098	1,519	832	43,747
Total assets acquired		1,667,076	866,876	644,670	155,530	2,194,371	251,673	493,314	1,449,384
Notes payable and other debt		41,436	36,300	5,136	0	412,825	57,219	0	355,606
Other liabilities		30,218	11,423	12,285	6,510	132,024	13,851	11,806	106,367
Total liabilities assumed		71,654	47,723	17,421	6,510	544,849	71,070	11,806	461,973
Noncontrolling interest assumed		11,785	10,113	0	1,672	37,653	7,292	0	30,361
Net assets acquired		1,583,637	809,040	627,249	147,348	1,611,869	173,311	481,508	957,050
Cash acquired		2,150	753	0	1,397	25,365	1,250	0	24,115
Total cash used	$ 350,000	$ 1,581,487	$ 808,287	$ 627,249	$ 145,951	$ 1,586,504	$ 172,061	$ 481,508	$ 932,935