Consolidated Statement of Shareholder's Interest - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Shareholder's Interest [Roll Forward]
Balance at beginning of period	$ 13,757
Net income	424	$ 234
Balance at end of period	14,130
Shareholder's Interest [Member]
Shareholder's Interest [Roll Forward]
Balance at beginning of period	5,166	5,166
Net income	0	0
Other Comprehensive Income (Loss), Net of Tax	0	0
Distributions declared	0
Balance at end of period	5,166	5,166
Accumulated Other Comprehensive Income/(Loss) (Note11) [Member]
Shareholder's Interest [Roll Forward]
Balance at beginning of period	(1,217)	(829)
Net income	0	0
Other Comprehensive Income (Loss), Net of Tax	149	(120)
Distributions declared	0
Balance at end of period	(1,068)	(949)
Retained Earnings [Member]
Shareholder's Interest [Roll Forward]
Balance at beginning of period	9,808	9,052
Other Comprehensive Income (Loss), Net of Tax	0	0
Distributions declared	(200)
Balance at end of period	10,032	9,286
Parent [Member]
Shareholder's Interest [Roll Forward]
Balance at beginning of period		13,389
Net income	424	234
Other Comprehensive Income (Loss), Net of Tax	149	(120)
Distributions declared	(200)
Balance at end of period	$ 14,130	$ 13,503