Investments in Equity Securities Available for Sale (Investments in Equity Securities Available for Sale) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 165,192	$ 160,295
Gross Unrealized, Gains	8,216	20,314
Gross Unrealized, Losses	(22,542)	(9,618)
Carrying value and fair value of equity securities	150,866	170,991
Common stocks
Schedule of Available-for-sale Securities [Line Items]
Cost	56,462	69,870
Gross Unrealized, Gains	0	11,929
Gross Unrealized, Losses	(19,189)	(5,453)
Carrying value and fair value of equity securities	37,273	76,346
Preferred stocks
Schedule of Available-for-sale Securities [Line Items]
Cost	108,730	90,425
Gross Unrealized, Gains	8,216	8,385
Gross Unrealized, Losses	(3,353)	(4,165)
Carrying value and fair value of equity securities	$ 113,593	$ 94,645