Segment Information (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) Segment	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Segment Information [Abstract]
Number of reportable segments | Segment				5
Segment Reporting Information [Line Items]
Revenue		$ 1,238,184	$ 748,393	$ 2,486,065	$ 1,495,668
Segment operating income	[1]	363,826	225,591	734,266	453,433
General and administrative (including non-cash stock-based compensation expense)		89,545	47,008	179,075	91,673
Transaction costs		421	6,808	7,163	17,652
Facility lease expense		91,338	70,030	185,809	139,899
Depreciation and amortization		225,645	71,088	446,072	141,404
Loss on facility lease termination		0	0	76,143	0
(Loss) Income from operations		(43,123)	30,657	(159,996)	62,805
Total assets		10,353,280		10,353,280		$ 10,521,363
Retirement Centers [Member]
Segment Reporting Information [Line Items]
Revenue	[2]	164,409	133,441	327,895	265,790
Segment operating income	[1]	72,044	56,891	142,568	113,121
Total assets		1,595,446		1,595,446		1,603,704
Assisted Living [Member]
Segment Reporting Information [Line Items]
Revenue	[2]	611,838	277,230	1,229,182	554,661
Segment operating income	[1]	223,359	104,246	446,865	209,238
Total assets		6,431,186		6,431,186		6,513,376
Brookdale Ancillary Services [Member]
Segment Reporting Information [Line Items]
Revenue	[2]	116,170	65,534	231,581	128,951
Segment operating income	[1]	17,724	12,905	40,466	25,658
Total assets		252,270		252,270		224,229
CCRCs Rental [Member]
Segment Reporting Information [Line Items]
Revenue	[2]	151,561	98,212	307,552	196,156
Segment operating income	[1]	35,860	25,693	74,431	52,523
Total assets		1,084,727		1,084,727		1,065,116
CCRCs Entry Fee [Member]
Segment Reporting Information [Line Items]
Revenue	[2]	0	79,100	0	158,269
Segment operating income	[1]	0	18,367	0	38,002
Management Services [Member]
Segment Reporting Information [Line Items]
Revenue	[3]	194,206	94,876	389,855	191,841
Segment operating income	[1]	14,839	$ 7,489	29,936	$ 14,891
Total assets		$ 989,651		$ 989,651		$ 1,114,938

[1] Segment operating income is defined as segment revenues less segment operating expenses (excluding depreciation and amortization).

[2] All revenue is earned from external third parties in the United States.

[3] Management services segment revenue includes reimbursements for which the Company is the primary obligor of costs incurred on behalf of managed communities.