Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Common stock, shares par value	$ 0.06	$ 0.06
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	89,311,000	89,020,000
Common stock, shares outstanding	89,311,000	89,020,000
Treasury stock, shares	2,956,000	3,068,000