Loans (Activity Related to Accretable Yield of Loans Acquired With Evidence of Credit Quality Deterioration Since Origination) (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Accretable yield, to be amortized to indemnification asset		$ 12,300		$ 12,300
Bank acquisitions
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Accretable yield, beginning balance		69,182	$ 97,674	77,485	$ 107,655
Acquisitions		0	0	898	0
Accretable yield amortized to interest income		(5,184)	(9,617)	(10,688)	(17,387)
Accretable yield amortized to indemnification asset	[1]	(4,089)	(11,161)	(7,665)	(16,809)
Reclassification from non-accretable difference	[2]	1,638	17,928	2,741	26,508
Increases (decreases) in interest cash flows due to payments and changes in interest rates		2,096	(2,722)	872	(7,865)
Accretable yield, ending balance	[3]	63,643	92,102	63,643	92,102
Life insurance premium finance loans acquisition
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Accretable yield, beginning balance		1,016	6,561	1,617	8,254
Acquisitions		0	0	0	0
Accretable yield amortized to interest income		(1,131)	(1,433)	(1,732)	(3,204)
Accretable yield amortized to indemnification asset	[1]	0	0	0	0
Reclassification from non-accretable difference	[2]	115	0	115	0
Increases (decreases) in interest cash flows due to payments and changes in interest rates		0	51	0	129
Accretable yield, ending balance	[3]	$ 0	$ 5,179	$ 0	$ 5,179

[1] Represents the portion of the current period accreted yield, resulting from lower expected losses, applied to reduce the loss share indemnification asset.

[2] Reclassification is the result of subsequent increases in expected principal cash flows.

[3] As of June 30, 2015, the Company estimates that the remaining accretable yield balance to be amortized to the indemnification asset for the bank acquisitions is $12.3 million. The remainder of the accretable yield related to bank acquisitions is expected to be amortized to interest income.