Other Investments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended			3 Months Ended	12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Jun. 30, 2013 Class of Stock [Domain]	Dec. 31, 2012 Debt Securities [Member]
Investment [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis						$ 10,000	$ 41,747
Available-for-sale Securities, Gross Unrealized Gains						0	223
Available-for-sale Securities, Gross Unrealized Losses						(80)	(316)
Other investments, at fair value	9,920		9,920		41,654	9,920	41,654
Gain on sale of investment securities	$ 0	$ 0	$ 451	$ 0