Organization And Description Of Business	9 Months Ended
Sep. 30, 2011
Organization And Description Of Business [Abstract]
Organization And Description Of Business	1. Organization and description of business PS Business Parks, Inc. ("PSB") was incorporated in the state of California in 1990. As of September 30, 2011, PSB owned 76.8% of the common partnership units of PS Business Parks, L.P. (the "Operating Partnership"). The remaining common partnership units are owned by Public Storage ("PS"). PSB, as the sole general partner of the Operating Partnership, has full, exclusive and complete responsibility and discretion in managing and controlling the Operating Partnership. PSB and the Operating Partnership are collectively referred to as the "Company." The Company is a fully-integrated, self-advised and self-managed real estate investment trust ("REIT") that acquires, develops, owns and operates commercial properties, primarily multi-tenant flex, office and industrial space. As of September 30, 2011 the Company owned and operated 21.8 million rentable square feet of commercial space located in eight states. The Company also manages 1.3 million rentable square feet on behalf of PS and its affiliated entities. References to the number of properties or square footage are unaudited and outside the scope of the Company's independent registered public accounting firm's review of the Company's financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States).

Organization And Description Of Business

9 Months Ended

Sep. 30, 2011

Organization And Description Of Business [Abstract]

Organization And Description Of Business

1. Organization and description of business

PS Business Parks, Inc. ("PSB") was incorporated in the state of California in 1990. As of September 30, 2011, PSB owned 76.8% of the common partnership units of PS Business Parks, L.P. (the "Operating Partnership"). The remaining common partnership units are owned by Public Storage ("PS"). PSB, as the sole general partner of the Operating Partnership, has full, exclusive and complete responsibility and discretion in managing and controlling the Operating Partnership. PSB and the Operating Partnership are collectively referred to as the "Company."

The Company is a fully-integrated, self-advised and self-managed real estate investment trust ("REIT") that acquires, develops, owns and operates commercial properties, primarily multi-tenant flex, office and industrial space. As of September 30, 2011 the Company owned and operated 21.8 million rentable square feet of commercial space located in eight states. The Company also manages 1.3 million rentable square feet on behalf of PS and its affiliated entities.

References to the number of properties or square footage are unaudited and outside the scope of the Company's independent registered public accounting firm's review of the Company's financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States).