FDIC loss share expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disclosure F D I C Loss Share Expense Income [Abstract]
Amortization				$ (934)
80% mirror accounting on credit impairment losses				104
80% mirror accounting on reimbursable expenses				537
80% mirror accounting on recoveries on covered assets, including rental income on OREOs, subject to reimbursement to the FDIC				(1,658)
Change in true-up payment obligation				(6,112)
Gain from the FDIC termination agreement			$ 0	102,752
Other				36
FDIC loss share (expense) income	$ 0	$ 0	$ 0	$ 94,725