Business Combinations (Details) - USD ($)	Sep. 30, 2019	Sep. 09, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Asset of acquiree entity	$ 3,350,724,000		$ 3,181,722,000
Goodwill	100,069,000		$ 98,569,000
United Community [Member]
Business Acquisition [Line Items]
Shares received by acquiree		0.3715
Strategic Investment Advisors, LLC [Member]
Business Acquisition [Line Items]
Asset of acquiree entity	115,000,000
Revenue of acquiree entity	600,000
Purchase price paid in cash at the closing	1,600,000
Purchase price paid in cash at the end of two-year earn-out	$ 400,000
Earn out period	2 years
Total purchase price	$ 2,000,000
Goodwill	1,500,000
Identifiable intangible assets	$ 500,000