Employee Retirement Plans (Schedule Of Total Expense For All Retirement Plans) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Employee Retirement Plans [Abstract]
Total retirement plan expense	$ 2,884	$ 2,610	$ 1,246

Period expense related to postemployment benefits.

No definition available.

Name:	us-gaap_PostemploymentBenefitsPeriodExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration