Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Commitments And Contingencies [Abstract]

Future Minimum Rental Commitments for All Long-Term Noncancelable Operating Leases

($ in millions)	Operating Leases
Year ending December 31:
2019	$	73
2020		18
2021		14
2022		13
2023		11
Thereafter		89
Total minimum lease payments	$	218

Future Payments for Obligations under Noncancelable Long Distance Contracts and Service Agreements

($ in millions)	Amount
Year ending December 31:
2019	$	44
2020		35
2021		26
2022		2
2023		2
Thereafter		7
Total	$	116

Outstanding Performance Letters of Credit

($ in millions)	Amount
CNA Financial Corporation (CNA)	$	49
AIG Insurance		43
Zurich		52
All other		1
Total	$	145