CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Common stock, par value (in dollars per share)	$ 0.10		$ 0.10
Common stock, shares authorized (in shares)	280,000,000		280,000,000
Common stock, shares issued (in shares)	147,694,000		146,415,000
Common stock, shares outstanding (in shares)	139,900,000		138,985,000
Treasury stock shares (in shares)	7,794,000		7,430,000
Tax effect of accumulated other comprehensive income	$ 0	$ 0