Restructuring and Severance - Additional Information (Details) $ in Millions	6 Months Ended
	Jun. 30, 2017 USD ($)
Restructuring Cost and Reserve [Line Items]
Unpaid severance and related charges	$ 8.1
Unpaid severance and related charges, period of payment	12 months
Severance costs
Restructuring Cost and Reserve [Line Items]
Unpaid severance and related charges	$ 0.7
RidgeWorth acquisition restructuring plan | Severance costs
Restructuring Cost and Reserve [Line Items]
Severance costs	8.6
Middle office outsourcing project restructuring plan | Severance costs
Restructuring Cost and Reserve [Line Items]
Severance costs	$ 0.3