Capital of the Operating Partnership (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2011
Equity Method Investment, Ownership Percentage	97.80%
Operating Partnership Units and LTIP Units [Member]
Partnership units, shares outstanding	133,853,140
LTIP Units, shares outstanding	386,441
Noncontrolling Interest [Member]
Minority interest redemption value	$ 56.6
Average closing price per share	$ 19.00
BIOMED REALTY TRUST, INC. [Member]
Equity Method Investment, Ownership Percentage	97.80%