Pension and Other Postretirement Benefits (Details 1) In Thousands, unless otherwise specified	12 Months Ended												12 Months Ended
	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2012 U.S. Pension Benefits [Member] USD ($)		Dec. 31, 2011 U.S. Pension Benefits [Member] USD ($)		Dec. 31, 2012 Foreign Pension Benefits [Member] USD ($)	Dec. 31, 2011 Foreign Pension Benefits [Member] USD ($)	Dec. 31, 2010 Foreign Pension Benefits [Member] USD ($)	Dec. 31, 2012 Foreign Pension Benefits [Member] GBP (£)	Dec. 31, 2011 Foreign Pension Benefits [Member] GBP (£)	Dec. 31, 2012 Other Postretirement Benefits [Member] USD ($)	Dec. 31, 2011 Other Postretirement Benefits [Member] USD ($)
Change in plan assets:
Fair value of plan assets, Beginning balance				$ 133,403	[1]	$ 135,730	[1]	$ 36,436	$ 34,836		£ 25,774	£ 23,443	$ 0	$ 0
Actual return on plan assets				14,240	[1]	(2,335)	[1]	3,586	1,014				0	0
Foreign currency exchange rate changes				0	[1]	0	[1]	1,734	(184)				0	0
Corporate contributions	0	7,000	5,000	36	[1]	7,045	[1]	1,786	1,693	1,420			642	650
Participant contributions				0	[1]	0	[1]	0	0				428	495
Gross benefits paid				(7,461)	[1]	(7,037)	[1]	(1,667)	(923)				(1,070)	(1,145)
Fair value of plan assets, Ending Balance				$ 140,218	[1]	$ 133,403	[1]	$ 41,875	$ 36,436	$ 34,836	£ 25,774	£ 23,443	$ 0	$ 0

[1] Includes the non-qualified defined benefit pension plan.