Business Combinations and Divestitures - Summary of Assets Held for Sale and Consideration Received and Gain on Sale (Details) - USD ($) $ in Thousands			3 Months Ended				12 Months Ended
	Apr. 20, 2020	Mar. 16, 2018	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Gain on sale of subsidiary or division			$ 0	$ 0	$ 9,758	$ 0	$ 9,758	$ 0	$ 1,071
Triumph Premium Finance
Business Acquisition [Line Items]
Loans	$ 84,504
Premises and equipment, net	45
Other assets	11
Total carrying amount	84,560
Other liabilities	479
Total carrying amount	84,081
Total consideration received	94,531
Gain on sale of division	10,450
Transaction costs	692
Gain on sale of subsidiary or division	$ 9,758
Triumph Healthcare Finance
Business Acquisition [Line Items]
Loans		$ 70,147
Premises and equipment, net		19
Goodwill		1,457
Intangible assets, net		958
Other assets		197
Total carrying amount		72,778
Total consideration received		74,017
Gain on sale of division		1,239
Transaction costs		168
Gain on sale of subsidiary or division		$ 1,071