Quarterly Results of Operations (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Results of Operations (Unaudited) [Abstract]
Revenues	$ 1,252,103	$ 1,083,935	$ 748,393	$ 747,275	$ 734,233	$ 728,999	$ 716,468	$ 712,266	$ 3,831,706	$ 2,891,966	$ 2,768,738
Asset impairment	9,992	0	0	0	10,233	504	2,154	0	9,992	12,891	27,677
Income from operations	(74,513)	(73,197)	30,657	32,148	30,183	33,983	28,435	38,687	(84,905)	131,288	80,939
Loss before income taxes	(173,996)	(153,109)	(2,333)	(1,293)	(2,491)	(7)	(4,036)	4,706	(330,731)	(1,828)	(64,948)
Net loss	(106,796)	(37,036)	(3,295)	(2,299)	(975)	(967)	(5,200)	3,558	(149,426)	(3,584)	(66,467)
Net loss attributable to Brookdale Senior Living Inc. common stockholders	$ (106,534)	$ (36,862)	$ (3,295)	$ (2,299)	$ (975)	$ (967)	$ (5,200)	$ 3,558	$ (148,990)	$ (3,584)	$ (66,467)
Weighted average basic and diluted (loss) earnings per share (in dollars per share)	$ (0.58)	$ (0.23)	$ (0.03)	$ (0.02)	$ (0.01)	$ (0.01)	$ (0.04)	$ 0.03	$ (1.01)	$ (0.03)	$ (0.54)