Accounting Policies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) state	Dec. 31, 2016 USD ($)
Number of states in which entity operates | state	19
Charge off threshold - small business commercial loans	$ 1
Minimum | Furniture and Equipment
Estimated useful life of property and equipment	1 year
Minimum | Software and Software Development Costs
Estimated useful life of property and equipment	1 year
Maximum | Furniture and Equipment
Estimated useful life of property and equipment	10 years
Maximum | Buildings
Estimated useful life of property and equipment	40 years
Maximum | Leasehold Improvements
Estimated useful life of property and equipment	15 years
Maximum | Software and Software Development Costs
Estimated useful life of property and equipment	10 years
PNC Foundation | Stock
Contribution of stock	$ 200	$ 75