Capital Lease Obligation (Tables)

12 Months Ended

Dec. 31, 2018

Leases [Abstract]

Schedule of capital lease undiscounted minimum future lease payments

The aggregate undiscounted minimum future lease payments are presented below:

	December 31, 2018
	($ in millions)
2019	$	10
2020	10
2021	10
Total minimum lease payments	30
Less imputed interest	(3		)
Present value of minimum lease payments	27
Less current maturities	(10		)
Present value of minimum lease payment, less current maturities	$	17