Fair Values of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Assets:
Investments	$ 3,727	$ 26,213
Total assets at fair value	3,727	26,213
Level 1 [Member]
Assets:
Investments	2,804
Total assets at fair value	2,804
Level 2 [Member]
Assets:
Investments		25,311
Total assets at fair value		25,311
Level 3 [Member]
Assets:
Investments	923	902
Total assets at fair value	$ 923	$ 902