Related Parties (Details)	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) office_space plane	Sep. 30, 2020 USD ($)	May 27, 2021 USD ($)
Related Party Transaction [Line Items]
lease term	75 months
Operating cash flows from operating leases		$ 8,100,000	$ 6,800,000	$ 16,000,000.0	$ 13,900,000
Total lease liability balance		72,300,000		72,300,000
Banker Steel Acquisition
Related Party Transaction [Line Items]
Bankers Steel debt - assumed						$ 6,300,000
Subordinated Debt
Related Party Transaction [Line Items]
Interest expense		100,000	0	200,000	0
Subordinated Debt | Banker Steel Acquisition
Related Party Transaction [Line Items]
Bankers Steel debt - assumed		6,300,000		$ 6,300,000
Subordinated Borrowing, Interest Rate				11.00%
Triple Ring | Affiliated Entity
Related Party Transaction [Line Items]
Expenses under service agreement		0	0	$ 0	1,000,000
Banker Steel | Affiliated Entity | Office Space
Related Party Transaction [Line Items]
Number of office spaces | office_space				2
Operating cash flows from operating leases				$ 10,000
Total lease liability balance		200,000		200,000
Lease expense		23,000	0	31,000	0
Banker Steel | Affiliated Entity | Planes
Related Party Transaction [Line Items]
Operating cash flows from operating leases				200,000
Total lease liability balance		4,100,000		4,100,000
Lease expense		$ 400,000	$ 0	$ 600,000	$ 0
Number of planes leased | plane				2