Retirement Plans (Schedule of Benefit Obligation, Fair Value of Assets, and Funded Status of the Plans) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of period	$ 16,112	$ 18,034
Service cost	23	33	31
Interest cost	771	707	748
Recognized net actuarial loss	2,753	(1,924)
Benefits paid	(734)	(738)
Benefit obligation at end of period	18,925	16,112	18,034
Fair value of assets at beginning of period	15,039	13,262
Actual gain (loss) on plan assets	601	2,019
Employer contribution	299	496
Fair value of assets at end of period	15,205	15,039	13,262
Funded status at end of period	(3,720)	(1,073)
Amounts recognized in the consolidated balance sheet consist of: Other long-term liabilities	(3,720)	(1,073)
Amounts recognized in accumulated other comprehensive income consist of: Net loss	4,429	1,375
Amounts recognized in accumulated other comprehensive income consist of: Prior service cost	3	4
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax, Total	4,432	1,379
United Kingdom Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of period	8,450	8,034
Interest cost	360	348	338
Recognized net actuarial loss	883	162
Benefits paid	(397)	(247)
Foreign currency exchange rate changes	(499)	153
Benefit obligation at end of period	8,797	8,450	8,034
Fair value of assets at beginning of period	6,769	6,051
Actual gain (loss) on plan assets	502	545
Employer contribution	284	303
Foreign currency exchange rate changes	(401)	117
Fair value of assets at end of period	6,757	6,769	6,051
Funded status at end of period	(2,040)	(1,681)
Amounts recognized in the consolidated balance sheet consist of: Other long-term liabilities	(2,040)	(1,681)
Amounts recognized in accumulated other comprehensive income consist of: Net loss	1,413	906
Amounts recognized in accumulated other comprehensive income consist of: Prior service cost	112	142
Amounts recognized in accumulated other comprehensive income consist of: Transition obligation	0	(50)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax, Total	$ 1,525	$ 998