Real Estate Properties - Schedule of Future Minimum Lease Payment Receivables and Payments (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Future minimum lease payments receivable:
2018	$ 187,984
2019	177,325
2020	158,000
2021	141,937
2022	131,362
Thereafter	693,119
Total	$ 1,489,727

Amount of lease payments to be received by lessor for operating lease.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=77888428&loc=SL77919396-209981

+ Details

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- Definition

Amount of lease payments to be received by lessor in fifth fiscal year following latest fiscal year for operating lease. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest statement of financial position date.

+ References

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- Definition

Amount of lease payments to be received by lessor in fourth year following latest fiscal year for operating lease. Excludes interim and annual periods when interim periods are reported on rolling approach, from latest statement of financial position date.

+ References

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Amount of lease payments to be received by lessor in next fiscal year following latest fiscal year for operating lease. Excludes interim and annual periods when interim periods are reported on rolling approach, from latest statement of financial position date.

+ References

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Amount of lease payments to be received by lessor after fifth fiscal year following latest statement of financial position date for operating lease. Excludes interim and annual periods when interim periods are reported on rolling approach, from latest statement of financial position date.

+ References

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- Definition

Amount of lease payments to be received by lessor in third fiscal year following latest fiscal year for operating lease. Excludes interim and annual periods when interim periods are reported on rolling approach, from latest statement of financial position date.

+ References

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- Definition

Amount of lease payments to be received by lessor in second fiscal year following latest fiscal year for operating lease. Excludes interim and annual periods when interim periods are reported on rolling approach, from latest statement of financial position date.

+ References

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