Credit Facility (Details) $ in Millions	Sep. 30, 2019 USD ($)
Revolving Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	$ 500.0
Unused line fee payment percentage	0.10%
Credit availability under the Loan Agreement	$ 150.0
Revolving Facility [Member] | Bank of America N.A. [Member]
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity	150.0
Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	350.0
Unsecured Revolving Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	$ 150.0
Revolving Credit Facility and Term Loan Facility
Line of Credit Facility [Line Items]
Effective rate percentage	2.79%