Acquisitions and Other Significant Transactions (Details) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended				1 Months Ended		9 Months Ended		1 Months Ended			1 Months Ended						0 Months Ended	1 Months Ended	3 Months Ended		9 Months Ended			0 Months Ended					1 Months Ended
	Aug. 31, 2014 Transaction	Sep. 30, 2014 Community	Sep. 30, 2013	Sep. 30, 2014 Option Community Pool	Sep. 30, 2013	Jul. 30, 2014	Dec. 31, 2013	Aug. 31, 2014 CCRCs JV [Member] Member Entity Community Property Representative	Aug. 31, 2014 RIDEA JV [Member] Community	Sep. 30, 2014 Minimum [Member]	Sep. 30, 2014 Maximum [Member]	Jul. 31, 2014 Retirement Centers [Member] Community	Sep. 30, 2014 Retirement Centers [Member]	Dec. 31, 2013 Retirement Centers [Member]	Jul. 31, 2014 Assisted Living [Member] Community	Sep. 30, 2014 Assisted Living [Member]	Dec. 31, 2013 Assisted Living [Member]	Sep. 30, 2014 Brookdale Ancillary Services [Member]	Jul. 31, 2014 Brookdale Ancillary Services [Member]	Dec. 31, 2013 Brookdale Ancillary Services [Member]	Jun. 04, 2013 Emeritus [Member]	Jul. 31, 2014 Emeritus [Member] Community	Sep. 30, 2014 Emeritus [Member]	Sep. 30, 2013 Emeritus [Member]	Sep. 30, 2014 Emeritus [Member] Community	Sep. 30, 2013 Emeritus [Member]	Jun. 04, 2013 Emeritus [Member]	Jun. 04, 2013 Emeritus [Member] Punitive damages [Member]	Jun. 04, 2013 Emeritus [Member] Compensatory damages [Member]	Jun. 04, 2013 Emeritus [Member] Joan Boice [Member] Child	Sep. 30, 2014 Emeritus [Member] Minimum [Member]	Sep. 30, 2014 Emeritus [Member] Maximum [Member]	Jul. 31, 2014 Acquisition of Communities [Member] Community
Business Acquisition [Line Items]
Percentage of voting interests acquired																						100.00%
Number of communities owned																						182
Number of communities operated under long-term leases																						311
Aggregate acquisition-date fair value of purchase consideration transferred																						$ 3,000,000,000
Shares issued in acquisition (in shares)																						47,600,000
Amount of mortgage indebtedness assumed																						1,400,000,000
Aggregate value of shares issued																						1,600,000,000
Number of underlying communities with which mortgage loans collateralized																									179
Weighted average interest rate (in hundredths)																															5.49%	6.06%
Debt maturity period										3 months	33 years
Preliminary Allocation of Purchase Price [Abstract]
Cash and cash equivalents																						28,000,000
Property, plant and equipment and leasehold intangibles																						5,547,000,000
Goodwill		743,220,000		743,220,000			109,553,000					20,000,000	27,395,000	7,121,000	487,000,000	589,015,000	102,432,000	126,810,000	127,000,000	0		634,000,000
Other intangible assets, net																						259,000,000
Other assets, net																						304,000,000
Trade Accounts Payable and accrued expenses																						(265,000,000)
Long-term debt																						(1,520,000,000)
Capital and Financing Lease obligations																						(2,736,000,000)
Deferred tax liability																						(367,000,000)
Other liabilities																						(234,000,000)
Noncontrolling interest																						(1,000,000)
Fair value of Brookdale common stock issued																						1,649,000,000
Pro-forma consolidated operational data [Abstract]
Total revenue																							1,260,000,000	1,221,000,000	3,802,000,000	3,598,000,000
Net loss attributable to common shares																							(34,000,000)	(88,000,000)	(66,000,000)	(312,000,000)
Basic and diluted net loss per share attributable to common shares																							$ (0.19)	$ (0.51)	$ (0.38)	$ (1.82)
Weighted average shares used in computing basic and diluted net loss per share (in shares)																							175,037,000	171,712,000	173,258,000	171,041,000
Transaction costs of acquisition		41,572,000	0	59,224,000	0																		35,600,000		49,900,000
Common stock, shares authorized (in shares)		400,000,000		400,000,000		400,000,000	200,000,000
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%	20.00%
Partners Joint Venture Ownership Percentage (in hundredths)								49.00%	80.00%
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
Cash contributed to venture by venture partner								323,500,000
Number of members on board								6
Number of representatives on board								3
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
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%		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		49
Number of communities with modified term				20
Number of communities purchased or sold								4				3			1																		4
Aggregate purchase price																																	51,400,000
Acquisition purchase price amount financed																																	17,000,000
Number of communities securing acquisition financing																																	3
Revenue of acquired business																							327,700,000
Income (Loss) of acquired business																							51,300,000
Loss Contingencies [Line Items]
Damages to be paid																												23,000,000	250,000
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				$ 330,405,000	$ 0