Equity of the Parent Company (Vested Ownership Interests) (Details)	Jun. 30, 2011	Dec. 31, 2010
Operating Partnership Units and LTIP Units	132,793,468	132,461,119
Percentage of Total	100.00%	100.00%
Operating partnership and LTIP units held by employees and related parties [Member]
Operating Partnership Units and LTIP Units	2,332,318	2,268,873
Percentage of Total	1.80%	1.70%
Operating partnership and LTIP units held by third parties [Member]
Operating Partnership Units and LTIP Units	588,801	588,801
Percentage of Total	0.40%	0.50%
BIOMED REALTY TRUST, INC. [Member]
Operating Partnership Units and LTIP Units	129,872,349	129,603,445
Percentage of Total	97.80%	97.80%