Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Interest income:
Cash and investments	$ 62	$ 3	$ 16
Total interest income	3,223	2,648	3,298
Total interest expense	2,102	1,316	2,046
Net interest income	1,121	1,332	1,252
Less: provisions for loan losses	79	(61)	155
Net interest income after provisions for loan losses	1,042	1,393	1,097
Other income (loss):
Servicing revenue	77	168	214
Asset recovery and business processing revenue	336	539	458
Other income	32	30	20
Gains on sales of loans		78
Gains (losses) on debt repurchases		(73)	(6)
Gains (losses) on derivative and hedging activities, net	171	64	(256)
Total other income	616	806	430
Expenses:
Salaries and benefits	444	569	497
Other operating expenses	332	638	467
Total operating expenses	776	1,207	964
Goodwill and acquired intangible asset impairment and amortization expense	19	30	22
Restructuring/other reorganization expenses	36	26	9
Total expenses	831	1,263	995
Income before income tax expense	827	936	532
Income tax expense	182	219	120
Net income	$ 645	$ 717	$ 412
Basic earnings per common share	$ 4.54	$ 4.23	$ 2.14
Average common shares outstanding	142	170	193
Diluted earnings per common share	$ 4.49	$ 4.18	$ 2.12
Average common and common equivalent shares outstanding	144	172	195
Dividends per common share	$ 0.64	$ 0.64	$ 0.64
FFELP Loans [Member]
Interest income:
Total interest income	$ 1,966	$ 1,464	$ 1,837
Less: provisions for loan losses			13
Private Education Loans [Member]
Interest income:
Total interest income	1,195	1,181	1,445
Less: provisions for loan losses	$ 79	$ (61)	$ 142