Summary of Significant Accounting Policies (Details 2) (USD $)	12 Months Ended
Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Tax treatment of dividends and distributions
Ordinary dividends	$ 0.607	$ 0.807	$ 0.699
Long-term capital gain	0.622	0.558	0.755
Unrecaptured section 1250 gain	$ 0.241	$ 0.275	$ 0.476
Distributions declared per Common Share outstanding	$ 1.470	$ 1.640	$ 1.930

Tax treatment of dividends and distributions.

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- Definition

Gain from a qualifying investment owned for longer than 12 months and then sold for a price greater than the purchase price. Taxes can be deferred until the sale of asset.

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- Definition

The cash outflow from distributions of an entity's earnings to common and preferred stockholders, including minority shareholders. Ordinary dividends are paid out of the earnings and profits of the entity and are taxed as ordinary income.

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- Definition

A type of depreciation-recapture income that is realized on the sale of depreciable real estate. Unrecaptured Section 1250 income is taxed at a 25% maximum capital gains rate (or in some cases less).

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- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

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