Acquired and Covered Loans - Acquired Loans (Details) - USD ($) $ in Thousands		Jun. 30, 2018	Dec. 31, 2017
Acquired Loans (Details) - Acquired Loans [Line Items]
Non-PCI	[1]	$ 1,251,970	$ 1,524,453
Total	[1]	1,364,326	1,661,906
Acquired loans
Acquired Loans (Details) - Acquired Loans [Line Items]
Non-PCI	[1]	1,243,420	1,512,664
Total	[1]	1,349,638	1,643,358
Covered loans
Acquired Loans (Details) - Acquired Loans [Line Items]
Non-PCI	[1]	8,550	11,789
Total	[1]	14,688	18,548
Receivables acquired with deteriorated credit quality
Acquired Loans (Details) - Acquired Loans [Line Items]
PCI	[1]	112,356	137,453
Receivables acquired with deteriorated credit quality | Acquired loans
Acquired Loans (Details) - Acquired Loans [Line Items]
PCI	[1]	106,218	130,694
Receivables acquired with deteriorated credit quality | Covered loans
Acquired Loans (Details) - Acquired Loans [Line Items]
PCI	[1]	$ 6,138	$ 6,759

[1] Included in loans in the Consolidated Statements of Condition.