Retirement Plans (Schedule of Changes In Benefit Obligation) (United Kingdom) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of period	$ 16,986	$ 14,955
Interest cost	748	799	264
Actuarial losses	980	1,896
Benefits paid	(711)	(694)
Benefit obligation at end of period	18,034	16,986	14,955
Fair value of assets at beginning of period	12,088	11,433
Actual gain (loss) on plan assets	1,127	266
Employer contribution	758	1,083
Fair value of assets at end of period	13,262	12,088	11,433
Funded status at end of period	(4,772)	(4,898)
Amounts recognized in the consolidated balance sheet consist of: Other long-term liabilities	(4,772)	(4,898)
United Kingdom Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of period	6,964	6,229
Interest cost	338	331
Actuarial losses	652	544
Plan transfers		194
Benefits paid	(236)	(309)
Foreign currency exchange rate changes	316	(25)
Benefit obligation at end of period	8,034	6,964
Fair value of assets at beginning of period	5,160	5,293
Actual gain (loss) on plan assets	596	(233)
Employer contribution	297	235
Foreign currency exchange rate changes	234	(20)
Fair value of assets at end of period	6,051	5,160
Funded status at end of period	(1,983)	(1,804)
Amounts recognized in the consolidated balance sheet consist of: Other long-term liabilities	$ (1,983)	$ (1,804)