Real Estate and Accumulated Depreciation (Schedule III Real Estate and Accumulated Depreciation) (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Encumbrances		$ 3,472,255
Initial Cost of Land		2,572,238
Initial Cost of Buildings & Improvements		27,040,378
Cost Capitalized Subsequent to Acquisition		1,373,415
Carrying Amount of Land		2,563,445
Carrying Amount of Buildings and Improvements		27,302,045
Accumulated Depreciation		3,796,297	$ 3,020,908	$ 2,386,658	$ 1,555,055
Investments In Real Property Owned Continuing Operations [Member]
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Encumbrances		3,472,255
Initial Cost of Land		2,572,238
Initial Cost of Buildings & Improvements		27,040,378
Cost Capitalized Subsequent to Acquisition		1,373,415
Carrying Amount of Land		2,563,445
Carrying Amount of Buildings and Improvements		27,302,045
Accumulated Depreciation		3,796,297
Triple Net [Member]
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Encumbrances		554,014
Initial Cost of Land		1,003,748
Initial Cost of Buildings & Improvements		10,800,837
Cost Capitalized Subsequent to Acquisition		600,549
Carrying Amount of Land		1,032,860
Carrying Amount of Buildings and Improvements		11,372,276
Accumulated Depreciation	[1]	1,539,033
Seniors Housing Operating [Member]
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Encumbrances		2,290,552
Initial Cost of Land		972,005
Initial Cost of Buildings & Improvements		10,569,105
Cost Capitalized Subsequent to Acquisition		446,629
Carrying Amount of Land		994,865
Carrying Amount of Buildings and Improvements		10,992,868
Accumulated Depreciation		1,463,201
Outpatient Medical [Member]
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Encumbrances		627,689
Initial Cost of Land		490,437
Initial Cost of Buildings & Improvements		4,274,941
Cost Capitalized Subsequent to Acquisition		278,333
Carrying Amount of Land		535,720
Carrying Amount of Buildings and Improvements		4,507,983
Accumulated Depreciation	[2]	794,063
Construction in Progress [Member]
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Encumbrances		0
Initial Cost of Land		0
Initial Cost of Buildings & Improvements		258,968
Cost Capitalized Subsequent to Acquisition		0
Carrying Amount of Land		0
Carrying Amount of Buildings and Improvements		258,968
Accumulated Depreciation		0
Assets Held-for-sale [Member]
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Encumbrances		0
Initial Cost of Land		106,048
Initial Cost of Buildings & Improvements		1,136,527
Cost Capitalized Subsequent to Acquisition		47,904
Carrying Amount of Land		0
Carrying Amount of Buildings and Improvements		169,950
Accumulated Depreciation	[2]	$ 0

[1] Please see Note 2 to our consolidated financial statements for information regarding lives used for depreciation and amortization.

[2] Represents real property asset associated with a capital lease.