Unsecured Line of Credit Payable - Narrative (Details) | Mar. 31, 2021USD ($) | Mar. 31, 2021USD ($) | Dec. 31, 2020USD ($) | Mar. 31, 2018USD ($)extension_option | Mar. 29, 2018USD ($) | Dec. 31, 2017USD ($) | Jul. 22, 2016USD ($) |
Line of Credit Facility [Line Items] | | | | | | | |
Repayment of outstanding borrowings | | $ 9,000,000 | | | | | |
Credit Agreement | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Credit agreement, aggregate maximum borrowing capacity including accordion feature | | | | $ 1,500,000,000 | | | |
2016 Term Loan | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Debt instrument face amount | | | | | | | $ 150,000,000 |
2016 Term Loan | Interest rate swaps | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Derivative notional amount | | | | | | | $ 150,000,000 |
Derivative fixed interest rate (percent) | | | | | | | 2.86% |
2018 Term Loan | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Debt instrument face amount | | | | | $ 250,000,000 | | |
2018 Term Loan | Interest rate swaps | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Derivative fixed interest rate (percent) | | | | | 2.87% | | |
2018 Term Loan A | Interest rate swaps | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Derivative notional amount | $ 150,000,000 | $ 150,000,000 | | | $ 150,000,000 | | |
Derivative fixed interest rate (percent) | 2.31% | 2.31% | | | 2.31% | | |
2018 Term Loan B | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Debt instrument face amount | | | | | $ 100,000,000 | | |
2018 Term Loan B | Interest rate swaps | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Derivative notional amount | $ 100,000,000 | $ 100,000,000 | | | $ 100,000,000 | | |
Derivative fixed interest rate (percent) | 3.71% | 3.71% | | | 3.71% | | |
Term loan | 2015 Term Loan | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Debt instrument face amount | | | | 150,000,000 | | | |
Repayment of borrowings | | | $ 150,000,000 | | | | |
Term loan | 2016 Term Loan | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Debt instrument face amount | | | | | | $ 150,000,000 | |
Term loan | 2018 Term Loan | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Debt instrument face amount | | | | $ 250,000,000 | | | |
All-in fixed interest rate (percent) | 2.87% | 2.87% | | | | | |
Term loan | 2018 Term Loan | LIBOR | Minimum | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Basis spread on variable rate (percent) | | 0.85% | | | | | |
Term loan | 2018 Term Loan | LIBOR | Maximum | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Basis spread on variable rate (percent) | | 1.75% | | | | | |
Term loan | 2018 Term Loan | Base Rate | Minimum | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Basis spread on variable rate (percent) | | 0.00% | | | | | |
Term loan | 2018 Term Loan | Base Rate | Maximum | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Basis spread on variable rate (percent) | | 0.75% | | | | | |
Revolving Credit Facility | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Revolving credit facility borrowing capacity | $ 700,000,000 | $ 700,000,000 | | | | | |
Debt instrument term (in years) | | | | 4 years | | | |
Number of extensions allowed | extension_option | | | | 2 | | | |
Term of allowable extension (in months) | | | | 6 months | | | |
Facility fee (percent) | 0.20% | | | | | | |
One-month LIBOR (percent) | 0.11% | 0.11% | | | | | |
Repayment of outstanding borrowings | | $ 36,000,000 | | $ 100,000,000 | | | |
Revolving Credit Facility | Minimum | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Facility fee (percent) | | 0.10% | | | | | |
Revolving Credit Facility | Maximum | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Facility fee (percent) | | 0.30% | | | | | |
Revolving Credit Facility | LIBOR | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Basis spread on variable rate (percent) | 1.00% | | | | | | |
Base rate component, spread on variable rate (percent) | | 1.00% | | | | | |
Revolving Credit Facility | LIBOR | Minimum | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Basis spread on variable rate (percent) | | 0.775% | | | | | |
Revolving Credit Facility | LIBOR | Maximum | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Basis spread on variable rate (percent) | | 1.55% | | | | | |
Revolving Credit Facility | Base Rate | Minimum | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Basis spread on variable rate (percent) | | 0.00% | | | | | |
Revolving Credit Facility | Base Rate | Maximum | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Basis spread on variable rate (percent) | | 0.55% | | | | | |
Revolving Credit Facility | Federal Funds Rate | | | | | | | |
Line of Credit Facility [Line Items] | | | | | | | |
Base rate component, spread on variable rate (percent) | | 0.50% | | | | | |