Cash Flows - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flow [Line Items]
Transferred to foreclosed property	$ 3,020	$ 4,150	$ 8,180
Unsettled sales of government guaranteed loans	32,900	27,500	29,900
Assets acquired, fair value	481,000	1,120,000	451,000
Liabilities assumed, fair value	350,000	1,000,000	440,000
Net assets acquired	130,000	115,000	$ 11,200
Common Stock
Cash Flow [Line Items]
Common stock issued as consideration	$ 45,700	$ 179,000