Significant Accounting Policies (Tables 2)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Net income per share table
Number of weighted average common shares outstanding	76,578,565	75,491,288	76,415,527	75,433,742
Assumed exercise of stock options	1,736,132	1,366,009	1,569,904	1,385,443
Average diluted shares outstanding	78,314,697	76,857,297	77,985,431	76,819,185