CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Securities held-to-maturity
Securities held-to-maturity, fair value (in dollars)	$ 375,320	$ 394,292
Preferred stock
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	43,222,184	38,200,883
Common stock, shares outstanding	43,222,184	38,200,883