Debt - Long term debt (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended	6 Months Ended
	Nov. 30, 2019	Mar. 31, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Unused fee (Percentage)				0.50%
Repayment of credit facility		$ 151,900
Distributions to members		250,000	$ 250,000
Redemption of members' interest		3,700	3,713
Payments of Debt Issuance Costs					$ 9,000
Write-off of deferred financing costs					2,121
Repayment of loan				$ 21,641	$ 153,826
Credit Facility [Member]
Debt Instrument [Line Items]
Borrowing capacity		425,000	425,000
Secured term loans
Debt Instrument [Line Items]
Debt balance outstanding				295,625			$ 246,250
Initial/credit facility term loan
Debt Instrument [Line Items]
Borrowing capacity		300,000	300,000
Repayment of loan	$ 50,000
Debt balance outstanding				$ 246,300
Credit facility Interest rate				2.67%
Delayed Draw Term Loan
Debt Instrument [Line Items]
Borrowing capacity	$ 100,000	$ 50,000	$ 50,000
Face amount				$ 50,000
Debt balance outstanding				$ 49,400
Credit facility Interest rate				2.67%
Debt term		24 months	24 months
Delayed Draw Term Loan | First Specified Repayment Period [Member]
Debt Instrument [Line Items]
Quarterly principal repayments		$ 300
Delayed Draw Term Loan | Second Specified Repayment Period [Member]
Debt Instrument [Line Items]
Quarterly principal repayments		600
Revolving credit facility/revolver
Debt Instrument [Line Items]
Borrowing capacity		$ 75,000	$ 75,000
Face amount						$ 20,000
Debt balance outstanding				$ 12,000			$ 12,000
Credit facility Interest rate				2.67%
Remaining maximum borrowings available				$ 60,500
Letter of Credit [Member]
Debt Instrument [Line Items]
Debt balance outstanding				$ 2,500