Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of goodwill by reporting unit

The following table presents changes in the carrying amount of goodwill by reporting unit during year ended December 31, 2018:

($ in thousands)	Consumer and Business Banking			Commercial Banking		Total
Beginning Balance, January 1, 2018	$	357,207		$	112,226	$	469,433
Disposition of the DCB branches	(3,886		)	—		(3,886		)
Ending Balance, December 31, 2018	$	353,321		$	112,226	$	465,547

Schedule of core deposit intangible assets and accumulated amortization

The following table presents the gross carrying amount of core deposit intangible assets and accumulated amortization as of December 31, 2018 and 2017:

($ in thousands)	December 31,
	2018			2017
Gross balance (1)	$	86,099		$	100,166
Accumulated amortization (1)	(71,570		)	(79,112		)
Net carrying balance (1)	$	14,529		$	21,054

(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 for the five years succeeding December 31, 2018 and thereafter:

	Amount
Years Ending December 31,	($ in thousands)
2019	$	4,518
2020	3,634
2021	2,749
2022	1,865
2023	1,199
Thereafter	564
Total	$	14,529