Guarantor Subsidiaries (Schedule Of Guarantor Subsidiaries - Statement Of Cash Flows) (Details) (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Net cash provided/(used) by operating activities	$ 107,936	$ 57,990
Capital expenditures	(23,459)	(19,107)
Business combinations, net of cash acquired	(3,689)	(30)
Other sources/(uses) - net	(829)	(448)
Net cash used by investing activities	(27,977)	(19,585)
Change in cash overdrafts payable	2,297	(184)
Dividends paid to shareholders	(9,393)	(8,682)
Purchases of treasury stock	(110,288)	(10,175)
Proceeds from exercise of stock options	7,979	3,632
Realized excess tax benefit on share based compensation	3,368	1,823
Debt issuance costs	(2,723)
Other sources/(uses) - net	226	222
Net cash used by financing activities	(108,534)	(13,364)
Increase/(Decrease) in Cash and Cash Equivalents	(28,575)	25,041
Cash and cash equivalents at beginning of year	49,917	112,416
Cash and cash equivalents at end of period	21,342	137,457
Parent Company [Member]
Net cash provided/(used) by operating activities	21,558	(4,364)
Capital expenditures	(23)	(14)
Other sources/(uses) - net	(150)	(116)
Net cash used by investing activities	(173)	(130)
Change in cash overdrafts payable	208	508
Change in intercompany accounts	60,028	40,895
Dividends paid to shareholders	(9,393)	(8,682)
Purchases of treasury stock	(110,221)	(10,164)
Proceeds from exercise of stock options	7,979	3,632
Realized excess tax benefit on share based compensation	3,368	716
Debt issuance costs	(2,723)
Other sources/(uses) - net	(5)	34
Net cash used by financing activities	(50,759)	26,939
Increase/(Decrease) in Cash and Cash Equivalents	(29,374)	22,445
Cash and cash equivalents at beginning of year	45,324	109,331
Cash and cash equivalents at end of period	15,950	131,776
Guarantor Subsidiaries [Member]
Net cash provided/(used) by operating activities	83,903	61,703
Capital expenditures	(22,378)	(18,399)
Business combinations, net of cash acquired	(3,689)	(30)
Other sources/(uses) - net	(713)	(313)
Net cash used by investing activities	(26,780)	(18,742)
Change in cash overdrafts payable	2,089	(692)
Change in intercompany accounts	(59,090)	(41,841)
Realized excess tax benefit on share based compensation		1,107
Net cash used by financing activities	(57,001)	(41,426)
Increase/(Decrease) in Cash and Cash Equivalents	122	1,535
Cash and cash equivalents at beginning of year	(1,571)	(1,221)
Cash and cash equivalents at end of period	(1,449)	314
Non-Guarantor Subsidiaries [Member]
Net cash provided/(used) by operating activities	2,475	651
Capital expenditures	(1,058)	(694)
Other sources/(uses) - net	34	(19)
Net cash used by investing activities	(1,024)	(713)
Change in intercompany accounts	(938)	946
Purchases of treasury stock	(67)	(11)
Other sources/(uses) - net	231	188
Net cash used by financing activities	(774)	1,123
Increase/(Decrease) in Cash and Cash Equivalents	677	1,061
Cash and cash equivalents at beginning of year	6,164	4,306
Cash and cash equivalents at end of period	$ 6,841	$ 5,367