Short-Term Borrowings and Credit Arrangements (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 600,000,000.0	$ 550,000,000.0
Letters of credit outstanding, amount	0	0
Credit Facility Borrowings and Letter of Credit, Amount Outstanding	413,000,000.0	318,000,000.0
Net availability as of December 31	187,000,000.0	232,000,000.0
Revolving Credit Facility Due 2028 [Member] | NW Corp
Line of Credit Facility [Line Items]
Maximum borrowing capacity	600,000,000.0	425,000,000.0
Revolving Credit Facility Due 2024
Line of Credit Facility [Line Items]
Maximum borrowing capacity	0	100,000,000.0
Swingline Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	0	25,000,000.0
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
SOFR borrowings	$ 413,000,000.0	$ 318,000,000.0