Equity - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2018	Feb. 28, 2018
Stockholders Equity Note [Line Items]
Net proceeds from issuance of common stock			$ 5,707,000	$ 198,333,000
Issuance of common stock		$ 12,511,000	5,547,000	190,108,000
Direct stock purchase and dividend reinvestment plan				$ 6,307,000
Share Repurchase Plan, February 2018
Stockholders Equity Note [Line Items]
Common stock authorized to repurchase by Board						$ 100,000,000
Available authorization remaining for repurchase	$ 100,000,000		$ 100,000,000
Convertible Debt Securities
Stockholders Equity Note [Line Items]
Securities excluded in the calculation of diluted earnings per share (in shares)			34,075,404
Equity awards
Stockholders Equity Note [Line Items]
Securities excluded in the calculation of diluted earnings per share (in shares)	11,561	8,996	16,405	8,186
At The Market Offerings | Common Stock
Stockholders Equity Note [Line Items]
Stock issuance program, authorized amount					$ 150,000,000
Issuance of common stock (in shares)			129,500
Net proceeds from issuance of common stock			$ 2,000,000
Remaining outstanding	$ 85,000,000		$ 85,000,000
Common Stock
Stockholders Equity Note [Line Items]
Issuance of common stock (in shares)		791,191	350,088	12,291,191
Issuance of common stock		$ 8,000	$ 3,000	$ 123,000
Direct stock purchase and dividend reinvestment plan (in shares)	0			399,838
Direct stock purchase and dividend reinvestment plan				$ 4,000