Goodwill and Other Intangible Assets (Schedule Of Components Of Other Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2011	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 73,730		$ 73,730
Accumulated Amortization	(29,137)		(26,141)
Net Carrying Amount	44,593		47,589
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	51,755		51,755
Accumulated Amortization	(22,039)		(19,585)
Net Carrying Amount	29,716		32,170
Useful Lives (in years)	11 years	11 years
Trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	15,400		15,400
Accumulated Amortization	(2,888)		(2,567)
Net Carrying Amount	12,512		12,833
Useful Lives (in years)	24 years	24 years
Software [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,300		4,300
Accumulated Amortization	(1,935)		(1,720)
Net Carrying Amount	2,365		2,580
Useful Lives (in years)	10 years	10 years
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,725		1,725
Accumulated Amortization	(1,725)		(1,719)
Net Carrying Amount	0		6
Useful Lives (in years)	3 years	3 years
Favorable leases [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	550		550
Accumulated Amortization	(550)		(550)
Net Carrying Amount	$ 0		$ 0
Useful Lives (in years)	2 years	2 years