Other Income and Other Expense (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Other income:
Interest income	$ 1,850	$ 3,255	$ 1,503
Investment gains - net	1,165	2,797	2,512
Miscellaneous	96	335	1,144
Total other income	3,111	6,387	5,159
Other expense:
Non-operating costs	(7,037)	(6,831)	(6,675)
Miscellaneous	(3,414)	(3,090)	(7,625)
Total other expense	$ (10,451)	$ (9,921)	$ (14,300)