Guarantor Subsidiaries (Schedule Of Guarantor Subsidiaries - Statement Of Cash Flows) (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Net cash provided by operating activities	$ 10,381,000	$ 48,541,000
Capital expenditures	(12,018,000)	(6,173,000)
Business combinations, net of cash acquired	(415,000)
Other sources/(uses) - net	311,000	(109,000)
Net cash used by investing activities	(12,122,000)	(6,282,000)
Change in cash overdrafts payable	226,000	(8,310,000)
Dividends paid to shareholders	(3,072,000)	(2,977,000)
Purchases of treasury stock	(1,431,000)	(24,260,000)
Proceeds from exercise of stock options	1,042,000	3,647,000
Debt issuance costs		(2,708,000)
Realized excess tax benefit on share based compensation	797,000	1,895,000
Other sources/(uses) - net	312,000	282,000
Net cash used by financing activities	(2,126,000)	(32,431,000)
Increase/(Decrease) in Cash and Cash Equivalents	(3,867,000)	9,828,000
Cash and cash equivalents at beginning of year	38,081,000	49,917,000
Cash and cash equivalents at end of period	34,214,000	59,745,000
Parent [Member]
Net cash provided by operating activities	(5,365,000)	(1,095,000)
Capital expenditures	(14,000)	(1,000)
Other sources/(uses) - net	220,000	(48,000)
Net cash used by investing activities	206,000	(49,000)
Change in cash overdrafts payable	(46,000)	668,000
Change in intercompany accounts	1,607,000	40,963,000
Dividends paid to shareholders	(3,072,000)	(2,977,000)
Purchases of treasury stock	(1,431,000)	(24,238,000)
Proceeds from exercise of stock options	1,042,000	3,647,000
Debt issuance costs		(2,708,000)
Realized excess tax benefit on share based compensation	797,000	1,895,000
Other sources/(uses) - net	(4,000)	13,000
Net cash used by financing activities	(1,107,000)	17,263,000
Increase/(Decrease) in Cash and Cash Equivalents	(6,266,000)	16,119,000
Cash and cash equivalents at beginning of year	32,470,000	45,324,000
Cash and cash equivalents at end of period	26,204,000	61,443,000
Guarantor Subsidiaries [Member]
Net cash provided by operating activities	14,625,000	48,715,000
Capital expenditures	(11,664,000)	(5,649,000)
Business combinations, net of cash acquired	(415,000)
Other sources/(uses) - net	113,000	(75,000)
Net cash used by investing activities	(11,966,000)	(5,724,000)
Change in cash overdrafts payable	272,000	(8,978,000)
Change in intercompany accounts	(841,000)	(40,314,000)
Net cash used by financing activities	(569,000)	(49,292,000)
Increase/(Decrease) in Cash and Cash Equivalents	2,090,000	(6,301,000)
Cash and cash equivalents at beginning of year	(1,422,000)	(1,571,000)
Cash and cash equivalents at end of period	668,000	(7,872,000)
Non-Guarantor Subsidiaries [Member]
Net cash provided by operating activities	1,121,000	921,000
Capital expenditures	(340,000)	(523,000)
Other sources/(uses) - net	(22,000)	14,000
Net cash used by investing activities	(362,000)	(509,000)
Change in intercompany accounts	(766,000)	(649,000)
Purchases of treasury stock		(22,000)
Other sources/(uses) - net	316,000	269,000
Net cash used by financing activities	(450,000)	(402,000)
Increase/(Decrease) in Cash and Cash Equivalents	309,000	10,000
Cash and cash equivalents at beginning of year	7,033,000	6,164,000
Cash and cash equivalents at end of period	$ 7,342,000	$ 6,174,000