CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Securities held-to-maturity, fair value	$ 199,010,000	$ 193,131,000
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	180,000,000	180,000,000
Common stock, shares issued (in shares)	77,064,000	77,484,000
Common stock, shares outstanding (in shares)	77,064,000	77,484,000