Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2019

Qualified Pension Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Components of Net Periodic Pension Costs

The following tables include the components of net periodic pension costs for qualified pension plans.

	Three Months Ended March 31, 2019
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	37		$	12		$	11		$	6		$	4		$	1		$	2		$	1
Interest cost on projected benefit obligation	83			20			26			12			14			5			6			3
Expected return on plan assets	(143		)	(38		)	(44		)	(23		)	(22		)	(8		)	(11		)	(5		)
Amortization of actuarial loss	24			6			9			3			6			1			2			2
Amortization of prior service credit	(8		)	(2		)	(1		)	—			—			—			—			(3		)
Net periodic pension costs	$	(7	)	$	(2	)	$	1		$	(2	)	$	2		$	(1	)	$	(1	)	$	(2	)

	Three Months Ended March 31, 2018
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	45		$	15		$	13		$	7		$	5		$	1		$	2		$	2
Interest cost on projected benefit obligation	75			18			24			11			13			5			6			3
Expected return on plan assets	(140		)	(37		)	(45		)	(21		)	(23		)	(7		)	(10		)	(6		)
Amortization of actuarial loss	33			7			11			5			6			1			2			3
Amortization of prior service credit	(8		)	(2		)	(1		)	—			—			—			—			(3		)
Net periodic pension costs	$	5		$	1		$	2		$	2		$	1		$	—		$	—		$	(1	)