Basis of Presentation and Summary of Significant Accounting Policies (Narrative, Goodwill and Other Intangible Assets) (Details) - USD ($)	3 Months Ended		12 Months Ended
	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2025
Goodwill and Intangible Assets [Line Items]
Goodwill impairment loss			$ 675,000,000
GMPD
Goodwill and Intangible Assets [Line Items]
Goodwill impairment loss	$ 90,000,000	$ 585,000,000	$ 675,000,000	$ 1,200,000,000
Goodwill, Impairment Loss, Statement of Income or Comprehensive Income [Extensible Enumeration]			Operating Income (Loss)	Operating Income (Loss)
Minimum
Goodwill and Intangible Assets [Line Items]
Discount Rate, fair value inputs					9.50%
Maximum
Goodwill and Intangible Assets [Line Items]
Discount Rate, fair value inputs					11.00%