Convertible Notes, Exchangeble Notes and Trust Preferred Securities (Details) (USD $)	12 Months Ended					12 Months Ended				12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Convertible Notes, Exchangeable Notes, and Trust Preferred Securities [Member]		Dec. 31, 2012 Six Percent Convertible Guaranteed Note [Member]	Dec. 31, 2010 Six Percent Convertible Guaranteed Note [Member]	Dec. 31, 2009 Six Percent Convertible Guaranteed Note [Member]	Mar. 31, 2010 Six Percent Convertible Guaranteed Note [Member]	Dec. 31, 2012 Five Percent Exchangeable Guaranteed Note [Member]	Dec. 31, 2010 Five Percent Exchangeable Guaranteed Note [Member]	Dec. 31, 2009 Five Percent Exchangeable Guaranteed Note [Member]	Dec. 31, 2007 Five Percent Exchangeable Guaranteed Note [Member]	Dec. 31, 2007 Six Point Eight Zero Four Percent Trust Preferred Securities [Member]	Dec. 31, 2012 Six Point Eight Zero Four Percent Trust Preferred Securities [Member]	Dec. 31, 2011 Six Point Eight Zero Four Percent Trust Preferred Securities [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Basis spread on variable rate														1.70%
Debt instrument amount						$ 83,896,000	$ 115,000,000			$ 0	$ 62,150,000		$ 450,000,000	$ 200,000,000
Debt interest rate percentage									6.00%				5.45%	6.804%
Percent of notes required to be repurchased at the option of the holders on set dates			100.00%
Convertible debt conversion ratio						144.2599
Convertible debt conversion price						$ 6.93
Debt conversion, original debt, amount						31,104,000
Debt Conversion, Converted Instrument, Shares Issued	4,487,060
Debt Conversion, Converted Instrument, Cash Payment During Conversion						2,427,000
Debt Conversion, Converted Instrument, Debt Satisfaction Expense						7,842,000
Exchangeable note exchange price													19.49
Repurchase of exchangeable notes	62,150,000	0	25,493,000							62,150,000	25,493,000
Debt satisfaction gains (charges)										(44,000)	(760,000)
Write-offs of debt discount and deferred financing costs										20,000	768,000
Carrying amount of debt component						78,127,000	105,149,000			0	62,102,000
Carrying amount of equity component						3,654,000	13,134,000			0	20,293,000
Effective interest rate						8.10%	8.10%			0.00%	7.00%
Aggregate if-converted value in excess of aggregate principal amount						42,579,000	7,907,000			0	0
Coupon interest						6,634,000	6,900,000	6,408,000		188,000	3,387,000	3,504,000
Discount amortization						1,868,000	1,938,000	1,776,000		34,000	664,000	689,000
Interest Expense						8,502,000	8,838,000	8,184,000		222,000	4,051,000	4,193,000
Scheduled Principal Payments for Debt Instruments [Abstract]
2013				0
2014				0
2015				0
2016				0
2017				83,896,000	[1]
Thereafter				129,120,000
Long-term Debt, Gross				213,016,000
Debt discount				(5,769,000)		(5,769,000)	(9,851,000)			0	(48,000)
Long-term debt				207,247,000
Principal amount outstanding on Trust Preferred Securities															$ 129,120,000	$ 129,120,000
Debt Instrument, Description of Variable Rate Basis														three month LIBOR plus 170 basis points

[1] Although the 6.00% Convertible Guaranteed Notes mature in 2030, the notes can be put to the Company in 2017. See note 22 for subsequent events.