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Derivative and Other Fair Value Instruments - Additional Information (Details) $ in Millions | 1 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Apr. 30, 2020 USD ($) DerivativeInstrument | Jun. 30, 2020 USD ($) | Dec. 31, 2019 USD ($)
Derivative [Line Items] |  |  |
Unrealized gain (loss) on interest rate cash flow hedges, pretax, accumulated other comprehensive income (loss) |  | $ 67.4 | $ 77.6
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net |  | $ 25.7 |
Forward Starting Swaps [Member] |  |  |
Derivative [Line Items] |  |  |
Payments for settlement of derivative instruments | $ 1.2 |  |
Forward starting swaps settled | DerivativeInstrument | 2 |  |
Increase (decrease) in charges hedge termination activities | $ 1.2 |  |
Mortgage notes period | 5 years |  |
Mortgages [Member] | Forward Starting Swaps [Member] |  |  |
Derivative [Line Items] |  |  |
Debt instrument face amount | $ 495.0 |  |
Secured conventional mortgage notes period | 10 years |  |

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- Definition The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121549185&loc=d3e80748-113994 + Details
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