Summary Of Significant Accounting Policies (Goodwill And Intangible Assets) (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Business Acquisition [Line Items]
Goodwill balance	$ 174.6	$ 174.6
Tenant intangibles net book value	15.9	16.4
Accumulated amortization, tenant intangibles	24.8	24.1
Amortization expense, tenant intangibles	10.5	11.9	13.3
Shurgard trade name, book value	18.8	18.8
Impairment charge on intangibles			0.2
Acquisition Of Self-Storage Facilities And Leasehold Interests [Member]
Business Acquisition [Line Items]
Increase in tenant intangibles	9.1	1.0
Consolidation Of Facilities [Member]
Business Acquisition [Line Items]
Increase in tenant intangibles	$ 0.9	$ 4.0

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Publisher FASB

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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