Business Segments - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2016 FinancialCenters Segment
Segment Reporting [Abstract]
Number of principal reporting segments | Segment	2
Bank operated Business Financial Centers, number | FinancialCenters	43
Bank operated Commercial Banking Centers, number | FinancialCenters	8
Consideration of Business Financial and Commercial Banking Centers | Segment	1