Goodwill and Other Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of goodwill

	September 30,		September 30,
(Dollars in thousands)	2021		2020
Balance, beginning of year	$	898,569	$	808,322
Goodwill acquired during the year	—		92,844
Purchase accounting adjustments	2,743		(2,732)
Balance, end of year	$	901,312	$	898,434
Accumulated impairment losses at end of year	$	—	$	—

Schedule of finite-lived intangible assets

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

	Three Months Ended						Nine Months Ended
	September 30,		June 30,		September 30,		September 30,		September 30,
(Dollars in thousands)	2021		2021		2020		2021		2020
Gross amount of intangible assets:
Beginning balance	$	145,212	$	145,212	$	145,212	$	145,212	$	125,945
Additions due to acquisitions	—		—		—		—		19,267
Ending balance	145,212		145,212		145,212		145,212		145,212
Accumulated amortization:
Beginning balance	(67,849)		(63,848)		(50,662)		(59,705)		(42,633)
Amortization	(3,912)		(4,001)		(4,538)		(12,056)		(12,567)
Ending balance	(71,761)		(67,849)		(55,200)		(71,761)		(55,200)
Net intangible assets	$	73,451	$	77,363	$	90,012	$	73,451	$	90,012