Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of changes in the carrying amount of goodwill by reporting unit

The following table presents changes in the carrying amount of goodwill by reporting units during the year ended December 31, 2019:

($ in thousands)	Consumer and Business Banking		Commercial Banking		Total
Beginning balance, January 1, 2019	$	353,321	$	112,226	$	465,547
Acquisition of East West Markets, LLC	—		150		150
Ending balance, December 31, 2019	$	353,321	$	112,376	$	465,697

Schedule of gross carrying amount of core deposit intangible assets and accumulated amortization

The following table presents the gross carrying amount of core deposit intangible and accumulated amortization as of December 31, 2020 and 2019:

($ in thousands)	December 31,
	2020		2019
Gross balance (1)	$	86,099	$	86,099
Accumulated amortization (1)	(79,722)		(76,088)
Net carrying balance (1)	$	6,377	$	10,011

(1) Excludes fully amortized core deposit intangible assets.

Schedule of estimated future amortization expense of the core deposit intangibles

The following table presents the estimated future amortization expense of core deposit intangibles as of December 31, 2020:

($ in thousands)	Amount
2021	$	2,749
2022	1,865
2023	1,199
2024	553
2025	11
Thereafter	—
Total	$	6,377