Debt - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Line of Credit Facility [Line Items]
Letters of credit outstanding	$ 6,800,000		$ 2,800,000
Estimated fair value of debt	106,200,000		101,200,000
Unrealized gain (loss) on derivative instruments	(54,265,000)	$ (9,039,000)
Interest rate swaps
Line of Credit Facility [Line Items]
Derivative instruments, liability position, fair value	72,700,000
Unrealized gain (loss) on derivative instruments	(54,300,000)	(9,000,000.0)
Expected reclassifications in next 12 months	30,000,000.0
Interest rate swaps | Interest expense
Line of Credit Facility [Line Items]
Reclassification of gain (loss) from AOCI to interest expense	1,800,000	$ (2,500,000)
Letters of credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	30,000,000.0
Unsecured debt | Unsecured term loans
Line of Credit Facility [Line Items]
Borrowings, fixed interest rate	$ 1,600,000,000		$ 1,600,000,000
Weighted-average fixed interest rate	3.56%		3.43%
Borrowings, floating interest rate	$ 345,000,000.0		$ 345,000,000.0
Weighted-average floating interest rate	2.55%		3.32%
Debt outstanding	$ 1,975,000,000		$ 1,975,000,000
Unsecured debt | Revolving credit facilities
Line of Credit Facility [Line Items]
Debt outstanding	643,168,000		165,000,000
Unsecured debt | Senior unsecured credit facility | Revolving credit facilities
Line of Credit Facility [Line Items]
Maximum borrowing capacity	650,000,000.0
Debt outstanding	643,168,000		165,000,000
Remaining borrowing capacity	0
Maximum borrowing capacity potential increase (up to)	$ 1,300,000,000
Unsecured debt | Senior unsecured credit facility | Revolving credit facilities | Minimum
Line of Credit Facility [Line Items]
Unused commitment fee annual rate	0.20%
Unsecured debt | Senior unsecured credit facility | Revolving credit facilities | Minimum | LIBOR
Line of Credit Facility [Line Items]
Credit facility borrowings LIBOR rate plus	1.45%
Unsecured debt | Senior unsecured credit facility | Revolving credit facilities | Maximum
Line of Credit Facility [Line Items]
Unused commitment fee annual rate	0.30%
Unsecured debt | Senior unsecured credit facility | Revolving credit facilities | Maximum | LIBOR
Line of Credit Facility [Line Items]
Credit facility borrowings LIBOR rate plus	2.25%
Unsecured debt | PHL unsecured credit facility | Revolving credit facilities
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 25,000,000.0
Debt outstanding	0		0
Remaining borrowing capacity	$ 25,000,000.0
Unsecured debt | PHL unsecured credit facility | Revolving credit facilities | Minimum | LIBOR
Line of Credit Facility [Line Items]
Credit facility borrowings LIBOR rate plus	1.45%
Unsecured debt | PHL unsecured credit facility | Revolving credit facilities | Maximum | LIBOR
Line of Credit Facility [Line Items]
Credit facility borrowings LIBOR rate plus	2.25%
Senior unsecured notes
Line of Credit Facility [Line Items]
Debt outstanding	$ 100,000,000		100,000,000
Senior unsecured notes | Series A Notes
Line of Credit Facility [Line Items]
Debt outstanding	$ 60,000,000		60,000,000
Stated interest rate	4.70%
Senior unsecured notes | Series B Notes
Line of Credit Facility [Line Items]
Debt outstanding	$ 40,000,000		40,000,000
Stated interest rate	4.93%
Cash flow hedging | Designated as hedging instrument | Interest rate swap, not yet effective
Line of Credit Facility [Line Items]
Notional value	$ 290,000,000.0		590,000,000.0
Cash flow hedging | Designated as hedging instrument | Interest rate swaps
Line of Credit Facility [Line Items]
Notional value	$ 1,630,000,000		$ 1,630,000,000