Marketable Securities (Realized and Unrealized Gain and Losses) (Details) (USD $)	1 Months Ended	12 Months Ended
	Jan. 31, 2011	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010
Sales Transaction of Marketable Securities, Unrealized Gain (Loss) [Abstract]
Equity securities, carrying value			$ 22,220,000	$ 22,168,000	$ 51,300,000
Equity securities, gross unrealized gain, before tax		24,200,000
Equity securities, gross unrealized gain, after tax			248,000	216,000	14,100,000
Equity securities, sale proceeds	51,900,000
Equity securities, gross realized gain, pre-tax	$ 24,900,000