Condensed Consolidated Balance Sheet (Parenthetical) (USD $)	Mar. 31, 2012	Dec. 31, 2011
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.1	$ 0.1
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares outstanding	61,880,310	61,782,180
Treasury stock, shares	126,036	95,409