Goodwill and Other Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of goodwill

	September 30,		September 30,
	2020		2019
	(Dollars in thousands)
Balance, beginning of year	$	808,322	$	808,726
Goodwill acquired during the year	92,844		—
Purchase accounting adjustments	(2,732)		(404)
Balance, end of year	$	898,434	$	808,322
Accumulated impairment losses at end of year	$	—	$	—

Schedule of finite-lived intangible assets

The change in the gross balance of core deposit intangibles and customer relationship intangibles, and the related accumulated amortization consisted of the following for the periods indicated:

	Three Months Ended						Nine Months Ended
	September 30,		June 30,		September 30,		September 30,		September 30,
	2020		2020		2019		2020		2019
	(Dollars in thousands)
Gross amount of intangible assets:
Beginning balance	$	145,212	$	125,945	$	125,945	$	125,945	$	125,945
Additions due to acquisitions	—		19,267		—		19,267		—
Ending balance	145,212		145,212		125,945		145,212		125,945
Accumulated amortization:
Beginning balance	(50,662)		(46,596)		(34,104)		(42,633)		(25,387)
Amortization	(4,538)		(4,066)		(4,281)		(12,567)		(12,998)
Ending balance	(55,200)		(50,662)		(38,385)		(55,200)		(38,385)
Net intangible assets	$	90,012	$	94,550	$	87,560	$	90,012	$	87,560