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Mortgage Notes Payable, Net (Narrative) (Details) $ in Thousands | 12 Months Ended
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Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($)
Mortgage Notes Payable [Line Items] |  |  |
Mortgage notes payable, net (amounts related to VIEs of $2,929,326 and $2,939,183 at December 31, 2018 and 2017, respectively) | $ 2,964,572 | $ 2,979,281 |
Number Of Mortgage Loans Accounted For Fair Value | 0 | 0 |
Interest Expense Decrease Due To Recording Mortgage Loans At Fair Value |  | $ 19,600 | $ 46,400
Minimum [Member] |  |  |
Mortgage Notes Payable [Line Items] |  |  |
Coupon/Stated Rate | 3.43% | 3.43% |
Number Real Estate Assets Used For Mortgage Loan Collateral | 1 |  |
Maximum [Member] |  |  |
Mortgage Notes Payable [Line Items] |  |  |
Coupon/Stated Rate | 7.69% | 7.69% |
Fixed Rate Mortgages [Member] |  |  |
Mortgage Notes Payable [Line Items] |  |  |
Mortgage notes payable, net (amounts related to VIEs of $2,929,326 and $2,939,183 at December 31, 2018 and 2017, respectively) | $ 3,000,000 | $ 3,000,000 |
Debt, Weighted Average Interest Rate | 3.77% | 3.78% |
Variable Rate Mortgages [Member] |  |  |
Mortgage Notes Payable [Line Items] |  |  |
Number of variable rate mortgage loans | 0 | 0 |

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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
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