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Derivative and Other Fair Value Instruments - Additional Information (Details) | 1 Months Ended | 12 Months Ended
--- | --- | ---
Jul. 31, 2019 USD ($) DerivativeInstrument | Jun. 30, 2019 USD ($) DerivativeInstrument | Nov. 30, 2018 USD ($) DerivativeInstrument | Feb. 28, 2018 USD ($) DerivativeInstrument | Aug. 31, 2017 USD ($) DerivativeInstrument | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($)
Derivative [Line Items] |  |  |  |  |  |  |  |
Unrealized gain (loss) on interest rate cash flow hedges, pretax, accumulated other comprehensive income (loss) |  |  |  |  |  | $ 77,600,000 | $ 65,000,000.0 |
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net |  |  |  |  |  | 24,900,000 |  |
Number of interest rate swaps matured | DerivativeInstrument | 6 |  |  |  |  |  |  |
Repayments of unsecured debt |  |  |  |  |  | $ 1,050,000,000 |  | $ 497,975,000
Forward Starting Swaps [Member] |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |
Proceeds from settlement of derivative instruments |  | $ 41,800,000 | $ 16,400,000 | $ 1,600,000 | $ 1,300,000 |  |  |
Forward starting swaps settled | DerivativeInstrument |  | 10 | 6 | 2 | 4 |  |  |
Interest expense |  | $ 200,000 | $ 120,000 |  |  |  |  |
Increase (decrease) in charges hedge termination activities |  | 41,600,000 | (16,500,000) | $ (1,600,000) | $ (1,300,000) |  |  |
Total commitment amount |  | $ 600,000,000.0 | $ 400,000,000.0 | $ 500,000,000.0 | $ 400,000,000.0 |  |  |
Debt instrument, term |  | 10 years | 10 years | 10 years | 10 years |  |  |
2.375% Notes [Member] |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |
Repayments of unsecured debt | $ 450,000,000.0 |  |  |  |  |  |  |
Debt instrument, interest rate, stated percentage | 2.375% |  |  |  |  |  |  |

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