Other Income and Other Expense (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other income:
Interest income	$ 1,239	$ 1,850	$ 3,255
Investment gains - net		1,165	2,797
Miscellaneous	367	96	335
Total other income	1,606	3,111	6,387
Other expense:
Non-operating costs	(7,777)	(7,037)	(6,831)
Investment loss - net	(2,453)
Miscellaneous	(9,612)	(3,414)	(3,090)
Total other expense	$ (19,842)	$ (10,451)	$ (9,921)