Accumulated Other Comprehensive (Loss) Income - Schedule of Changes in Components of AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance, shareholders' equity	$ 4,738	$ 4,229	$ 3,586
AOCI activity before reclassifications	(755)	4
Amounts reclassified from AOCI	10	(6)
Other comprehensive (loss) income for the period	(745)	(2)	139
Ending balance, shareholders' equity	9,662	4,738	4,229
Total accumulated other comprehensive (loss) income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance, shareholders' equity	10	12	(127)
Other comprehensive (loss) income for the period	(745)	(2)	139
Ending balance, shareholders' equity	(735)	10	12
Unrealized (loss) gain on securities available for sale
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance, shareholders' equity	(9)	79
AOCI activity before reclassifications	(730)	(62)
Amounts reclassified from AOCI	0	(26)
Other comprehensive (loss) income for the period	(730)	(88)
Ending balance, shareholders' equity	(739)	(9)	79
Unrealized loss on securities available for sale transferred to securities held to maturity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance, shareholders' equity	(7)	4
AOCI activity before reclassifications	0	(10)
Amounts reclassified from AOCI	1	(1)
Other comprehensive (loss) income for the period	1	(11)
Ending balance, shareholders' equity	(6)	(7)	4
Defined benefit pension items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance, shareholders' equity	26	(71)
AOCI activity before reclassifications	(25)	76
Amounts reclassified from AOCI	9	21
Other comprehensive (loss) income for the period	(16)	97
Ending balance, shareholders' equity	$ 10	$ 26	$ (71)