Employee Benefit Plans (Estimated Cash Flows) (Details)	12 Months Ended
	Dec. 31, 2015 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Reduction in PNC Benefit Payments Due to Medicare Part D Subsidy, 2016	$ 1,000,000
Reduction in PNC Benefit Payments Due to Medicare Part D Subsidy, 2017	1,000,000
Reduction in PNC Benefit Payments Due to Medicare Part D Subsidy, 2018	1,000,000
Reduction in PNC Benefit Payments Due to Medicare Part D Subsidy, 2019	1,000,000
Reduction in PNC Benefit Payments Due to Medicare Part D Subsidy, 2020	1,000,000
Reduction in PNC Benefit Payments Due to Medicare Part D Subsidy, 2021 - 2025	5,000,000
Qualified Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Estimated future benefit payments during 2016	273,000,000
Estimated future benefit payments during 2017	289,000,000
Estimated future benefit payments during 2018	305,000,000
Estimated future benefit payments during 2019	303,000,000
Estimated future benefit payments during 2020	304,000,000
Estimated future benefit payments during 2021-2025	1,560,000,000
Nonqualified Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Estimated 2016 employer contributions	27,000,000
Estimated future benefit payments during 2016	27,000,000
Estimated future benefit payments during 2017	26,000,000
Estimated future benefit payments during 2018	28,000,000
Estimated future benefit payments during 2019	25,000,000
Estimated future benefit payments during 2020	24,000,000
Estimated future benefit payments during 2021-2025	105,000,000
Gross PNC Benefit Payments
Defined Benefit Plan Disclosure [Line Items]
Estimated 2016 employer contributions	2,000,000
Estimated future benefit payments during 2016	25,000,000
Estimated future benefit payments during 2017	26,000,000
Estimated future benefit payments during 2018	27,000,000
Estimated future benefit payments during 2019	27,000,000
Estimated future benefit payments during 2020	28,000,000
Estimated future benefit payments during 2021-2025	$ 133,000,000