Acquired and Covered Loans - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Certain Loans Acquired in Transfer Accounted for as Debt Securities Accretable Yield Movement Schedule [Line Items]
Outstanding balance of PCI loans	$ 251,800		$ 251,800		$ 175,200
Renewed non-purchased credit impaired loans	490,000		490,000		458,000
FDIC indemnification asset	1,500		1,500		$ 2,100
Accretion on acquired loans	3,670	$ 2,922	7,871	$ 6,540
Acquired and covered receivables
Certain Loans Acquired in Transfer Accounted for as Debt Securities Accretable Yield Movement Schedule [Line Items]
Accretion on acquired loans	$ 10,300	$ 4,400	$ 16,700	$ 9,600