Senior Notes, Convertible Notes and Trust Preferred Securities - Schedule of Long-term Debt Instruments (Details) - 6.00% Convertible Guaranteed Note [Member] - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2010
Debt Instrument [Line Items]
Debt interest rate percentage				6.00%
Principal amount of debt component	$ 12,400,000	$ 16,228,000		$ 115,000,000
Unamortized discount	(220,000)	(564,000)
Carrying amount of debt component	12,180,000	15,664,000
Carrying amount of equity component	$ (34,784,000)	$ (33,160,000)
Effective interest rate	7.80%	8.10%
Aggregate if-converted value in excess of aggregate principal amount	$ 2,863,000	$ 10,432,000
Coupon interest	765,000	1,545,000	$ 2,296,000
Discount amortization	228,000	438,000	658,000
Interest Expense	$ 993,000	$ 1,983,000	$ 2,954,000