Common Stock Activity (Summary of Share Activity) (Details)	1 Months Ended	3 Months Ended	12 Months Ended
	Jul. 31, 2012	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Common Stock [Member]	Dec. 31, 2011 Common Stock [Member]	Dec. 31, 2010 Common Stock [Member]	Dec. 31, 2012 Treasury Stock [Member]	Dec. 31, 2011 Treasury Stock [Member]	Dec. 31, 2009 Treasury Stock [Member]
Rollforward of Share Activity, Common and Treasury Shares
Beginning balance, shares					80,569,000	78,215,000		(4,593,663)	0	0
Treasury shares, beginning balance			4,593,663					4,593,663	0
Shares issued for stock options exercises			391,949	1,132,396	391,949	1,132,396	231,599
Shares issued for restricted stock awards					348,000	647,000
Other shares issued					13,000	39,000
Shares issued for acquisition of business						5,129,642	1,875,000
Common stock repurchases	2,000,000	2,900,000		4,600,000	4,873,623	4,593,663		4,873,623	4,593,663
Ending balance, shares					76,448,000	80,569,000	78,215,000	(9,467,286)	(4,593,663)	0
Treasury shares, ending balance			9,467,286	4,593,663				9,467,286	4,593,663