Interest Expense (Details) - USD ($) $ in Thousands			1 Months Ended		3 Months Ended		12 Months Ended
	Feb. 17, 2021	Dec. 22, 2020	Feb. 28, 2021	Dec. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Interest and Debt Expense [Abstract]
Interest Expense, Debt					$ 16,865	$ 24,092
Accretion of fair value adjustment on Senior Notes					1,271	549
Amortization of Debt Issuance Costs					4,031	1,031
Interest Expense, Total					$ 22,167	25,672
Subordinated Borrowing, Interest Rate		4.625%
Line of Credit Facility, Interest Rate During Period					3.50%		4.50%
Debt Instrument [Line Items]
Repayments of Secured Debt					$ 150,000	0
Amortization of Debt Issuance Costs					4,031	$ 1,031
Payments of Debt Restructuring Costs					1,600
2018 Term Loan Facility
Debt Instrument [Line Items]
Repayments of Secured Debt							$ 900,000	$ 350,000
2018 Term Loan Facility | Senior Subordinated Notes
Interest and Debt Expense [Abstract]
Amortization of Debt Issuance Costs					900
Debt Instrument [Line Items]
Repayments of Secured Debt	$ 150,000		$ 150,000	$ 500,000
Accretion Expense					1,500
Amortization of Debt Issuance Costs					$ 900