Acquisitions of Real Estate Property (Estimated Fair Value) (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended	12 Months Ended		1 Months Ended
	Aug. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jan. 31, 2015
Business Acquisition [Line Items]
Total cash used	$ 350,000
2014 Acquisitions
Business Acquisition [Line Items]
Land and improvements		145,867
Buildings and improvements		1,628,056
Acquired lease intangibles		65,335
Other assets		12,614
Total assets acquired		1,851,872
Notes payable and other debt		241,077
Other liabilities		133,506
Total liabilities assumed		374,583
Net assets acquired		1,477,289
Cash acquired		8,931
Total cash used		1,468,358
2014 Acquisitions | Triple Net Leased Properties
Business Acquisition [Line Items]
Land and improvements		45,586
Buildings and improvements		546,849
Acquired lease intangibles		28,883
Other assets		227
Total assets acquired		621,545
Notes payable and other debt		12,927
Other liabilities		8,609
Total liabilities assumed		21,536
Net assets acquired		600,009
Cash acquired		227
Total cash used		599,782
2014 Acquisitions | Senior Living Operations
Business Acquisition [Line Items]
Land and improvements		100,281
Buildings and improvements		1,081,207
Acquired lease intangibles		36,452
Other assets		12,387
Total assets acquired		1,230,327
Notes payable and other debt		228,150
Other liabilities		124,897
Total liabilities assumed		353,047
Net assets acquired		877,280
Cash acquired		8,704
Total cash used		868,576
2013 Acquisitions
Business Acquisition [Line Items]
Land and improvements		100,908
Buildings and improvements		1,521,596
Acquired lease intangibles		36,227
Other assets		8,345
Total assets acquired		1,667,076
Notes payable and other debt		41,436
Other liabilities		30,218
Total liabilities assumed		71,654
Noncontrolling interest assumed		11,785
Net assets acquired		1,583,637
Cash acquired		2,150
Total cash used		1,581,487
2013 Acquisitions | Triple Net Leased Properties
Business Acquisition [Line Items]
Land and improvements		51,419
Buildings and improvements		803,227
Acquired lease intangibles		8,945
Other assets		3,285
Total assets acquired		866,876
Notes payable and other debt		36,300
Other liabilities		11,423
Total liabilities assumed		47,723
Noncontrolling interest assumed		10,113
Net assets acquired		809,040
Cash acquired		753
Total cash used		808,287
2013 Acquisitions | Senior Living Operations
Business Acquisition [Line Items]
Land and improvements		45,566
Buildings and improvements		579,577
Acquired lease intangibles		16,920
Other assets		2,607
Total assets acquired		644,670
Notes payable and other debt		5,136
Other liabilities		12,285
Total liabilities assumed		17,421
Noncontrolling interest assumed		0
Net assets acquired		627,249
Cash acquired		0
Total cash used		627,249
2013 Acquisitions | MOB Operations
Business Acquisition [Line Items]
Land and improvements		3,923
Buildings and improvements		138,792
Acquired lease intangibles		10,362
Other assets		2,453
Total assets acquired		155,530
Notes payable and other debt		0
Other liabilities		6,510
Total liabilities assumed		6,510
Noncontrolling interest assumed		1,672
Net assets acquired		147,348
Cash acquired		1,397
Total cash used		145,951
2012 Acquisitions
Business Acquisition [Line Items]
Land and improvements			195,047
Buildings and improvements			1,724,848
Construction in progress			25,579
Acquired lease intangibles			202,799
Other assets			46,098
Total assets acquired			2,194,371
Notes payable and other debt			412,825
Other liabilities			132,024
Total liabilities assumed			544,849
Noncontrolling interest assumed			37,653
Net assets acquired			1,611,869
Cash acquired			25,365
Total cash used			1,586,504
2012 Acquisitions | Triple Net Leased Properties
Business Acquisition [Line Items]
Land and improvements			21,881
Buildings and improvements			225,950
Construction in progress			0
Acquired lease intangibles			2,323
Other assets			1,519
Total assets acquired			251,673
Notes payable and other debt			57,219
Other liabilities			13,851
Total liabilities assumed			71,070
Noncontrolling interest assumed			7,292
Net assets acquired			173,311
Cash acquired			1,250
Total cash used			172,061
2012 Acquisitions | Senior Living Operations
Business Acquisition [Line Items]
Land and improvements			60,662
Buildings and improvements			413,750
Construction in progress			0
Acquired lease intangibles			18,070
Other assets			832
Total assets acquired			493,314
Notes payable and other debt			0
Other liabilities			11,806
Total liabilities assumed			11,806
Noncontrolling interest assumed			0
Net assets acquired			481,508
Cash acquired			0
Total cash used			481,508
2012 Acquisitions | MOB Operations
Business Acquisition [Line Items]
Land and improvements			112,504
Buildings and improvements			1,085,148
Construction in progress			25,579
Acquired lease intangibles			182,406
Other assets			43,747
Total assets acquired			1,449,384
Notes payable and other debt			355,606
Other liabilities			106,367
Total liabilities assumed			461,973
Noncontrolling interest assumed			30,361
Net assets acquired			957,050
Cash acquired			24,115
Total cash used			932,935
American Realty Capital Healthcare Trust | Subsequent Event
Business Acquisition [Line Items]
Notes payable and other debt				167,000
Total cash used				$ 11,000