CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.50	$ 0.50
Common stock, shares authorized	155,000,000	155,000,000
Common stock, shares issued	105,868,064	105,871,064
Common stock, shares outstanding	105,868,064	105,871,064