Unsecured Line of Credit Payable - Narrative (Details)		1 Months Ended	3 Months Ended			9 Months Ended
	Sep. 27, 2021 USD ($)	Aug. 31, 2021 USD ($)	Sep. 30, 2021 USD ($) extension_option	Sep. 30, 2020 USD ($)	Mar. 31, 2018 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Mar. 29, 2018 USD ($)	Jul. 22, 2016 USD ($)
Line of Credit Facility [Line Items]
Gain (loss) on extinguishment of debt			$ (12,727,000)	$ 0		$ (12,727,000)	$ 262,000
Interest rate swaps
Line of Credit Facility [Line Items]
Derivative notional amount										$ 100,000,000
Credit Agreement
Line of Credit Facility [Line Items]
Credit agreement, aggregate maximum borrowing capacity including accordion feature			1,500,000,000			1,500,000,000
2016 Term Loan
Line of Credit Facility [Line Items]
Debt instrument face amount										150,000,000
2018 Term Loan
Line of Credit Facility [Line Items]
Debt instrument face amount									$ 250,000,000
2018 Term Loan A | Interest rate swaps
Line of Credit Facility [Line Items]
Derivative notional amount	$ 150,000,000		100,000,000			100,000,000		$ 150,000,000	150,000,000
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		50,000,000			50,000,000			$ 100,000,000
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			$ 250,000,000
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%
Notes payable
Line of Credit Facility [Line Items]
Gain (loss) on extinguishment of debt		$ (12,300,000)
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
Gain (loss) on extinguishment of debt			$ (200,000)
Additional loan origination costs			$ 4,800,000			$ 4,800,000
Facility fee (percent)						0.20%
One-month LIBOR (percent)			0.08%			0.08%
Repayment of outstanding borrowings	150,000,000				$ 100,000,000	$ 150,000,000
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)						0.85%
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)			0.70%
Revolving Credit Facility | LIBOR | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate (percent)			1.40%
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)			0.40%
Revolving Credit Facility | Federal Funds Rate
Line of Credit Facility [Line Items]
Base rate component, spread on variable rate (percent)			0.50%
Revolving Credit Facility | Term loan
Line of Credit Facility [Line Items]
Gain (loss) on extinguishment of debt	$ (300,000)