Goodwill and Acquired Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The following table presents changes in the carrying amount of goodwill:

	For the Year Ended December 31,
(In thousands)	2020		2019		2018
Beginning of year	$	205,286	$	204,753	$	147,578
Changes from business combinations	15,890		533		57,175
Total	$	221,176	$	205,286	$	204,753

Acquired intangible assets consist of core deposit intangibles

The change in balance for CDI is as follows:

	For the Year Ended December 31,
(In thousands)	2020		2019		2018
Beginning of year	$	18,305	$	24,807	$	18,937
Acquired CDI, including measurement period adjustments	2,129		(676)		10,170
Amortization expense	(5,857)		(5,826)		(4,300)
End of year	$	14,577	$	18,305	$	24,807
(In months)
Remaining average amortization period for CDI	44		47		58

Gross Carrying Amount and Accumulated Amortization of Intangible Asset

The gross carrying amount and accumulated amortization of the Company's CDI subject to amortization as of:

	December 31, 2020				December 31, 2019
(In thousands)	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
Core deposit intangible	$	38,144	$	(23,567)	$	36,015	$	(17,710)