Acquisitions and Other Significant Transactions (Details) (USD $)	0 Months Ended	1 Months Ended		12 Months Ended
	Jun. 04, 2013 Child	Aug. 31, 2014 Entity Member Unit Representative Community Property	Jul. 31, 2014 Community	Dec. 31, 2014 Community	Dec. 31, 2013 Community	Dec. 31, 2012	Jul. 30, 2014
Business Acquisition [Line Items]
Percentage of voting interests acquired			100.00%
Number of communities operated under long-term leases				583	329
Aggregate acquisition-date fair value of purchase consideration transferred			$ 3,000,000,000
Amount of mortgage indebtedness assumed			1,400,000,000
Number of underlying communities with which mortgage loans collateralized			179
Transaction costs of acquisition				66,949,000	3,921,000	0
Common stock, shares authorized (in shares)				400,000,000	200,000,000		400
Number of venture transactions entered by the entity		2
Term of master agreement		15 years
Percentage of interest acquired in joint venture (in hundredths)		51.00%
Partners Joint Venture Ownership Percentage (in hundredths)		49.00%
Number of wholly-owned entities contributed to the venture by the entity		8
Number of communities owned by the entity		8
Number of wholly-owned entities contributed to the venture by venture partner		3
Number of properties owned by venture partner		3
Number of communities owned by venture partner		2
Number of Communities Deconsolidated				10
Cash contributed to venture by venture partner		323,500,000
Number of members on board		6
Number of representatives on board		3
Number of communities under master lease and security agreement		112
Number of communities under triple net leases agreement		41
Number of pools under amended master leases agreement		3
Master leases term for Pool one communities		14 years
Master leases term for Pool two communities		15 years
Master leases term for Pool three communities		16 years
Number of extension options		2
Term of extension option		10 years
Base rent as per amended master leases agreement		158,000,000
Maximum available reimbursement for capital expenditures by co venturer		100,000,000
Initial lease rate for lessor reimbursements for capital expenditures (in hundredths)		7.00%
Number of communities for which purchase option included in master lease		10
Maximum aggregate purchase price of communities under purchase option		60,000,000
Number Of Communities With Cancelled Purchase Options		49
Number of communities with modified term		20
Number of communities purchased or sold				4
Income (Loss) of acquired business				128,200,000
Extinguishment of Debt, Amount				275,900,000
Preliminary Allocation of Purchase Price [Abstract]
Goodwill acquired during period				639,292,000
Pro-forma consolidated operational data [Abstract]
Total revenue				5,055,000,000	4,853,000,000
Net loss attributable to common shares				(103,000,000)	(424,000,000)
Basic and diluted net loss per share attributable to common shares				$ (0.59)	$ (2.48)
Weighted average shares used in computing basic and diluted net loss per share (in shares)				175,823	171,255
Loss Contingencies [Line Items]
Number of adult children of Joan Boice	3
Attorney fees awarded to plaintiffs' lawyer	4,100,000
Cash deposit made to collateralize the bond	20,900,000
Stockholders' Equity Note [Abstract]
Stock Issued During Period, Shares, New Issues				10,298,506
Proceeds from public equity offering, net				330,386,000	0	0
Deferred Offering Costs				400,000
Weighted average interest rate				5.50%
Extinguishment of Debt, Amount				275,900,000
Common stock issued in connection with Emeritus acquisition				1,648,782,000
Stock Issued During Period, Shares, Acquisitions				47,584,000
Punitive damages [Member]
Loss Contingencies [Line Items]
Damages to be paid	23,000,000
Compensatory damages [Member]
Loss Contingencies [Line Items]
Damages to be paid	250,000
CCRCs JV [Member]
Business Acquisition [Line Items]
Number of communities purchased or sold		4
RIDEA JV [Member]
Business Acquisition [Line Items]
Percentage of interest acquired in joint venture (in hundredths)		20.00%
Partners Joint Venture Ownership Percentage (in hundredths)		80.00%
Advance from co venturers affiliate		68,000,000
Number of communities contributed by venture partner		49
Lease restructuring fee payable to co venturer		34,000,000
Period with in which lease restructuring fee payable		2 years
Extinguishment of Debt, Amount				68,000,000
Stockholders' Equity Note [Abstract]
Extinguishment of Debt, Amount				68,000,000
Minimum [Member]
Business Acquisition [Line Items]
Weighted average interest rate (in hundredths)			5.49%
Debt maturity period			3 months
Maximum [Member]
Business Acquisition [Line Items]
Weighted average interest rate (in hundredths)			6.06%
Debt maturity period			33 years
Retirement Centers [Member]
Business Acquisition [Line Items]
Number of communities purchased or sold			3
Preliminary Allocation of Purchase Price [Abstract]
Goodwill acquired during period				20,499,000
Assisted Living [Member]
Business Acquisition [Line Items]
Number of communities purchased or sold			1
Preliminary Allocation of Purchase Price [Abstract]
Goodwill acquired during period				491,983,000
Brookdale Ancillary Services [Member]
Preliminary Allocation of Purchase Price [Abstract]
Goodwill acquired during period				126,810,000
Emeritus [Member]
Business Acquisition [Line Items]
Number of communities operated			493
Number of communities operated under long-term leases			311
Transaction costs of acquisition				57,100,000
Number of communities owned by the entity			182
Revenue of acquired business				785,500,000
Preliminary Allocation of Purchase Price [Abstract]
Cash and cash equivalents				28,000,000
Property, plant and equipment and leasehold intangibles				5,506,000,000
Other intangible assets, net				259,000,000
Other assets, net				308,000,000
Trade Accounts Payable and accrued expenses				(297,000,000)
Long-term debt				(1,516,000,000)
Capital and Financing Lease obligations				(2,692,000,000)
Deferred tax liability				(337,000,000)
Other liabilities				(248,000,000)
Noncontrolling interest				(1,000,000)
Fair value of Brookdale common stock issued				1,649,000,000
Acquisition of Communities [Member]
Business Acquisition [Line Items]
Number of communities purchased or sold			4
Aggregate purchase price			51,400,000
Acquisition purchase price amount financed			17,000,000
Number of communities securing acquisition financing			3
Communities agreed to purchase under HCP Master Lease Purchase Option [Member]
Business Acquisition [Line Items]
Aggregate purchase price				$ 60,000,000
Pro-forma consolidated operational data [Abstract]
Number of facilities purchased or sold				9
Acquired property plant and equipment [Member] | Minimum [Member]
Pro-forma consolidated operational data [Abstract]
Fair Value Inputs, Cap Rate			5.50%
Acquired property plant and equipment [Member] | Maximum [Member]
Pro-forma consolidated operational data [Abstract]
Fair Value Inputs, Cap Rate			9.75%
Acquired capital and financing lease obligations [Member] | Minimum [Member]
Pro-forma consolidated operational data [Abstract]
Fair Value Inputs, Cap Rate			6.00%
Acquired capital and financing lease obligations [Member] | Maximum [Member]
Pro-forma consolidated operational data [Abstract]
Fair Value Inputs, Cap Rate			10.75%
Acquired long-term debt obligations [Member] | Minimum [Member]
Pro-forma consolidated operational data [Abstract]
Fair Value Inputs, Cap Rate			3.00%
Acquired long-term debt obligations [Member] | Maximum [Member]
Pro-forma consolidated operational data [Abstract]
Fair Value Inputs, Cap Rate			7.00%