Goodwill and Other Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of core deposit intangibles and other intangibles

For CDIs and other intangibles, changes in the gross carrying amount, accumulated amortization, and net book value were as follows:

($ in Thousands)	Nine Months Ended September 30, 2020		Year Ended December 31, 2019
Core deposit intangibles
Gross carrying amount at the beginning of the year	$	80,730	$	58,100
Additions during the period	7,379		22,630
Accumulated amortization	(19,003)		(12,456)
Net book value	$	69,107	$	68,274
Amortization during the year	$	6,547	$	7,130
Other intangibles
Gross carrying amount at the beginning of the year	$	38,970	$	44,887
Additions during the period	200		—
Reductions due to sale	(17,435)		(217)
Accumulated amortization	(20,335)		(24,643)
Net book value	$	1,400	$	20,027
Amortization during the year	$	1,393	$	2,818

Summary of changes in balance of mortgage servicing rights asset and mortgage servicing rights valuation allowance

A summary of changes in the balance of the MSRs asset and the MSRs valuation allowance is as follows:

($ in Thousands)	Nine Months Ended September 30, 2020			Year Ended December 31, 2019
Mortgage servicing rights
Mortgage servicing rights at beginning of period	$	67,607		$	68,433
Additions from acquisition	1,357			—
Additions	11,495			11,606
Amortization	(16,416)			(12,432)
Mortgage servicing rights at end of period	$	64,043		$	67,607
Valuation allowance at beginning of period	$	(302)		$	(239)
(Additions) recoveries, net	(18,481)			(63)
Valuation allowance at end of period	$	(18,782)		$	(302)
Mortgage servicing rights, net	$	45,261		$	67,306
Fair value of mortgage servicing rights	$	45,303		$	72,532
Portfolio of residential mortgage loans serviced for others (“servicing portfolio”)	$	8,218,839		$	8,488,969
Mortgage servicing rights, net to servicing portfolio	0.55		%	0.79		%
Mortgage servicing rights expense(a)	$	34,897		$	12,494

(a) Includes the amortization of mortgage servicing rights and additions / recoveries to the valuation allowance of mortgage servicing rights, and is a component of mortgage banking, net on the consolidated statements of income

Summary of estimated future amortization expense

The following table shows the estimated future amortization expense for amortizing intangible assets:

($ in Thousands)	Core Deposit Intangibles		Other Intangibles		Mortgage Servicing Rights
Three Months Ending December 31, 2020	$	2,203	$	50	$	4,245
2021	8,811		200		15,333
2022	8,811		200		10,935
2023	8,811		200		8,030
2024	8,811		200		6,095
2025	8,811		200		4,764
Beyond 2025	22,849		350		14,640
Total Estimated Amortization Expense	$	69,107	$	1,400	$	64,043