Secured Revolving Credit Facility (Details)	1 Months Ended
	Apr. 30, 2019 USD ($) item	Jan. 31, 2019 USD ($)
Minimum
Letters of Credit
Commitment fee (as a percent)	0.20%
Maximum
Letters of Credit
Commitment fee (as a percent)	0.30%
Revolving line of credit
Letters of Credit
Maximum borrowing capacity	$ 150,000,000.0
Incremental borrowing facility	$ 75,000,000.0
Borrowing facility multiple factor - first year | item	6
Borrowing facility multiple factor - second year | item	5
Borrowing facility multiple factor - thereafter	$ 4
Amount outstanding	0	$ 0
Letter of credit
Letters of Credit
Maximum borrowing capacity	10,000,000.0
Swingline
Letters of Credit
Maximum borrowing capacity	$ 10,000,000.0
Eurodollar Loans and ABR Loans
Letters of Credit
Applicable margin reduction (as a percent)	0.25%
Gross proceeds	$ 100,000,000.0
Eurodollar Loans | LIBOR | Minimum
Letters of Credit
Margin (as a percent)	2.75%
Eurodollar Loans | LIBOR | Maximum
Letters of Credit
Margin (as a percent)	3.25%
ABR Loans | Federal funds rate
Letters of Credit
Margin (as a percent)	0.50%
ABR Loans | Eurodollar Rate
Letters of Credit
Margin (as a percent)	1.00%
ABR Loans | Eurodollar Rate | Minimum
Letters of Credit
Margin (as a percent)	1.75%
ABR Loans | Eurodollar Rate | Maximum
Letters of Credit
Margin (as a percent)	2.25%