Goodwill and Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands					12 Months Ended
	Dec. 06, 2019	Nov. 01, 2019	Sep. 03, 2019	Jul. 01, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Goodwill and Intangible Assets [Line Items]
Amortization of intangible assets					$ 19,620	$ 16,015	$ 12,557
Customer Relationships [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted-average remaining lives of intangible assets					10 years 6 months
Trade Name [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted-average remaining lives of intangible assets					9 years 3 months 18 days
Core Deposits [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted-average remaining lives of intangible assets					3 years 6 months
Non-Compete Agreements [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted-average remaining lives of intangible assets					6 years 1 month 6 days
Investment Banking Backlog [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted-average remaining lives of intangible assets					8 years 1 month 6 days
Acquired Technology [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted-average remaining lives of intangible assets					1 year 8 months 12 days
Mooreland Partners [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Date of acquisition				Jul. 01, 2019	Jul. 01, 2019
B&F Capital Markets, Inc. [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Date of acquisition			Sep. 03, 2019
MainFirst Bank AG [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Date of acquisition		Nov. 01, 2019
GMP Capital Inc. [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Date of acquisition	Dec. 06, 2019