Purchase Credit Impaired ("PCI") Loans - Rollforward of PCI Loans, Net of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 64,583	$ 83,693
Principal reductions and interest payments	(11,768)	(13,214)
Accretion of loan discount	3,431	5,989
Changes in contractual and expected cash flows due to remeasurement	(5,410)	(8,783)
Reductions due to disposals	(13,678)	(9,201)
Balance at end of period	47,978	76,050
Contractual Cashflows
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	116,689	178,145
Principal reductions and interest payments	(11,768)	(13,214)
Accretion of loan discount	0	0
Changes in contractual and expected cash flows due to remeasurement	(6,144)	(12,100)
Reductions due to disposals	(21,663)	(13,831)
Balance at end of period	89,402	139,000
Non-accretable Difference
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	26,765	65,719
Principal reductions and interest payments	0	0
Accretion of loan discount	0	0
Changes in contractual and expected cash flows due to remeasurement	(1,522)	(26,187)
Reductions due to disposals	(4,912)	(2,794)
Balance at end of period	23,375	36,738
Accretable Yield
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	25,341	28,733
Principal reductions and interest payments	0	0
Accretion of loan discount	3,431	5,989
Changes in contractual and expected cash flows due to remeasurement	(788)	(5,304)
Reductions due to disposals	(3,073)	(1,836)
Balance at end of period	$ 18,049	$ 26,212