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Acquisitions and Dispositions - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified | 9 Months Ended
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Sep. 30, 2014 Trust Investment | Sep. 30, 2013
Business Combinations [Abstract] |  |
Number of limited partnerships | 18 |
Number of business income trusts | 2 |
Purchase of non-controlling interests | $ 233 | $ 14

X
- Definition Number of business income trusts. + References No definition available. + Details
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X
- Definition Number of limited partnerships. + References No definition available. + Details
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- Details
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X
- Definition The cash outflow during the period for redemption of redeemable noncontrolling interests. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
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