Fair Value - Fair Value Measurement (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assumed Gain/(Loss) From Loan Sale	$ (1,049)
Interest Rate Movement Effect	4,482
Servicing Rights Value	10,132
Security Price Change	(4,701)
Total Fair Value Measurement Gain/(Loss)	8,864
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	683,479
Assumed Gain/(Loss) From Loan Sale	(1,031)
Interest Rate Movement Effect	3,536
Servicing Rights Value	7,245
Total Fair Value Measurement Gain/(Loss)	9,750
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	913,334
Security Price Change	(4,701)
Total Fair Value Measurement Gain/(Loss)	(4,701)
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	256,259
Assumed Gain/(Loss) From Loan Sale	(18)
Interest Rate Movement Effect	946
Servicing Rights Value	2,887
Total Fair Value Measurement Gain/(Loss)	$ 3,815