Consolidated Condensed Statements Of Cash Flow (Parenthetical) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012
Shares repurchased under the share repurchase program, value	$ 81,156	[1]	$ 83,946	[1]
Stock Repurchase Authorization [Member]
Shares repurchased under the share repurchase program, value	77,900		81,400
Variable Prepaid Share Repurchase Agreement [Member]
Shares repurchased under the share repurchase program, value	$ 40,000

[1] 2013 and 2012 include $77.9 million and $81.4 million, respectively, repurchased under the share repurchase program launched in fourth quarter 2011. 2013 includes $40.0 million associated with a prepaid variable share repurchase agreement.