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Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Jun. 07, 2020	Dec. 31, 2019	Sep. 30, 2019
Goodwill [Line Items]
Goodwill	$ 1,566,524		$ 1,002,900	$ 1,002,900
Core deposit and other intangibles	171,637		$ 49,816	$ 53,083
CSFL
Goodwill [Line Items]
Goodwill	563,600	$ 563,625
Goodwill related to the CSFL merger	563,600
Core Deposits \| CSFL
Goodwill [Line Items]
Intangible assets related to the CSFL merger	125,900
Client list intangibles \| CSFL
Goodwill [Line Items]
Intangible assets related to the CSFL merger	$ 10,000