Mortgage Servicing Assets (Tables)

6 Months Ended

Jun. 30, 2021

Changes in Carrying Amount of Mortgage Servicing Assets

Changes in the carrying amount of commercial mortgage servicing assets are summarized as follows:


	Three months ended June 30,				Six months ended June 30,
in millions	2021		2020		2021		2020
Balance at beginning of period	$	588	$	543	$	578	$	539
Servicing retained from loan sales	28		53		57		77
Purchases	7		7		14		18
Amortization	(30)		(30)		(59)		(59)
Temporary (impairments) recoveries	7		(8)		10		(10)
Balance at end of period	$	600	$	565	$	600	$	565
Fair value at end of period	$	704	$	663	$	704	$	663

Changes in the carrying amount of residential mortgage servicing assets are summarized as follows:


	Three months ended June 30,				Six months ended June 30,
in millions	2021		2020		2021		2020
Balance at beginning of period	$	72	$	40	$	58	$	46
Servicing retained from loan sales	12		8		23		13
Purchases	—		—		—		—
Amortization	(5)		(3)		(10)		(5)
Temporary (impairments) recoveries	(2)		1		6		(8)
Balance at end of period	$	77	$	46	$	77	$	46
Fair value at end of period	$	81	$	46	$	81	$	46

Schedule of Range and Weighted-Average of Significant Unobservable Inputs

The range and weighted average of the significant unobservable inputs used to determine the fair value of our commercial mortgage servicing assets at June 30, 2021, and June 30, 2020, along with the valuation techniques, are shown in the following table:


dollars in millions		June 30, 2021						June 30, 2020
Valuation Technique	Significant Unobservable Input	Range				Weighted Average		Range				Weighted Average

Discounted cash flow	Expected defaults	1.01	%	2.00	%	1.16	%	1.00	%	2.00	%	1.15	%
	Residual cash flows discount rate	7.48	%	10.53	%	9.24	%	6.97	%	16.16	%	9.42	%
	Escrow earn rate	1.14	%	1.26	%	1.19	%	0.78	%	2.25	%	1.66	%

	Loan assumption rate	—	%	1.73	%	1.43	%	—	%	3.37	%	1.32	%

The range and weighted-average of the significant unobservable inputs used to fair value our mortgage servicing assets at June 30, 2021, and June 30, 2020, along with the valuation techniques, are shown in the following table:


		June 30, 2021						June 30, 2020
Valuation Technique	Significant Unobservable Input	Range				Weighted Average		Range					Weighted Average

Discounted cash flow	Prepayment speed	7.70	%	52.85	%	13.27	%	12.29		%	55.18	%	16.89	%
	Discount rate	7.50	%	8.60	%	7.54	%	7.55		%	9.27	%	7.64	%
	Servicing cost	$62.00		5,125		70.00		$	62.00		5,135		77.45