Fair Value - Fair Value Measurement (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assumed Gain/(Loss) From Loan Sale	$ (277)
Interest Rate Movement Effect	(11,644)
Servicing Rights Value	8,043
Security Price Change	8,064
Total Fair Value Measurement Gain/(Loss)	4,186
Mortgage Banking [Member] | Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Rate Lock Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	458,161
Assumed Gain/(Loss) From Loan Sale	(339)
Interest Rate Movement Effect	(1,682)
Servicing Rights Value	4,097
Total Fair Value Measurement Gain/(Loss)	2,076
Mortgage Banking [Member] | Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Forward Sales Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	738,637
Security Price Change	8,064
Total Fair Value Measurement Gain/(Loss)	8,064
Mortgage Banking [Member] | Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Mortgages Held for Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	357,912
Assumed Gain/(Loss) From Loan Sale	62
Interest Rate Movement Effect	(9,962)
Servicing Rights Value	3,946
Total Fair Value Measurement Gain/(Loss)	$ (5,954)