Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2019

Compensation And Retirement Disclosure [Abstract]

Net Periodic Benefit Cost (Credit)

Components of net periodic benefit cost recorded by DESC were as follows:

(millions)	Pension Benefits						Other Postretirement Benefits
Three Months Ended June 30,	2019			2018			2019		2018
Service cost	$	3		$	4		$	—	$	1
Interest cost		7			7			2		2
Expected return on assets		(10	)		(12	)		—		—
Amortization of actuarial losses		3			3			—		1
Curtailment(1)		6			—			3		—
Net periodic benefit cost	$	9		$	2		$	5	$	4
Six Months Ended June 30,
Service cost	$	7		$	8		$	1	$	2
Interest cost		15			15			4		4
Expected return on assets		(20	)		(24	)		—		—
Amortization of actuarial losses		7			5			—		1
Curtailment(1)		6			—			3		—
Net periodic benefit cost	$	15		$	4		$	8	$	7

(1) Related to a voluntary retirement program.