Equity - Additional Information (Details) - USD ($)	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
	Feb. 28, 2019	Dec. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Class of Stock [Line Items]
Forward equity sales agreement, initial net price (in usd per share)					$ 31.84
Issuance of common stock, net			$ 102,429,000	$ 877,000	$ 509,242,000	$ 4,310,000
Common Stock
Class of Stock [Line Items]
Issuance of common stock, net (in shares)			0		5,900,000
Issuance of common stock, net					$ 189,000,000
At-The-Market Program 2018
Class of Stock [Line Items]
Issuance of common stock, net (in shares)							5,400,000
Weighted average net price (in usd per share)		$ 28.27					$ 28.27
Proceeds from issuance of common stock							$ 154,000,000
ATM aggregate amount authorized	$ 1,000,000,000.0
Issuance of common stock, net					$ 171,000,000
Share settlement (in shares)			5,500,000		5,500,000
Remainder outstanding (in shares)			9,300,000		9,300,000
Forward Equity Offering
Class of Stock [Line Items]
Issuance of common stock, net (in shares)			3,600,000		5,100,000
Forward equity sales agreement, initial net price (in usd per share)		$ 28.60			$ 30.91
Issuance of common stock, net			$ 100,000,000		$ 142,000,000
Maximum shares issuable under forward equity sales agreement (in shares)		15,250,000
Remainder outstanding (in shares)			10,150,000		10,150,000
Forward rate, remainder outstanding (in usd per share)			$ 31.06		$ 31.06
ATM aggregate amount remaining					$ 341,000,000
Option indexed to issuers equity, term		1 year			1 year
Forward Equity Offering | Common Stock
Class of Stock [Line Items]
Issuance of common stock, net (in shares)		2,000,000
Weighted average net price (in usd per share)		$ 28.60					$ 28.60
Proceeds from issuance of common stock		$ 57,000,000
2019 ATM Program
Class of Stock [Line Items]
Forward equity sales agreement, initial net price (in usd per share)			$ 31.10		$ 31.23
Maximum shares issuable under forward equity sales agreement (in shares)			1,200,000		14,800,000
Minimum | Forward Equity Offering
Class of Stock [Line Items]
Weighted average net price (in usd per share)			$ 27.85		$ 27.85
Maximum | Forward Equity Offering
Class of Stock [Line Items]
Weighted average net price (in usd per share)			$ 27.93		$ 27.93