Investments and Fair Value Measurements (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Nov. 04, 2011
Assets:
Investment securities available for sale	$ 180,836		$ 172,534
Liabilities:
Income (loss) from embedded derivatives	(1,650)	3,049
Nonrecurring nonfinancial assets subject to fair value measurements	0		0
Fair Value, Measurements, Recurring [Member] | Total
Assets:
Money market funds	130,030		130,733
Certificates of deposit	3,350		2,961
Bonds	5,237		5,337
Warrants	1,602		1,935
Total	321,055		313,500
Liabilities:
Fair value of derivatives embedded within convertible debt	193,975		112,062
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Money market funds	130,030		130,733
Certificates of deposit	0		0
Cash and Cash Equivalents, Fair Value Disclosure	5,237		5,337
Warrants	0		0
Total	265,756		260,304
Liabilities:
Fair value of derivatives embedded within convertible debt	0		0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2)
Assets:
Money market funds	0		0
Certificates of deposit	3,350		2,961
Cash and Cash Equivalents, Fair Value Disclosure	0		0
Warrants	0		0
Total	53,697		51,261
Liabilities:
Fair value of derivatives embedded within convertible debt	0		0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Assets:
Money market funds	0		0
Certificates of deposit	0		0
Cash and Cash Equivalents, Fair Value Disclosure	0		0
Warrants	1,602		1,935
Total	1,602		1,935
Liabilities:
Fair value of derivatives embedded within convertible debt	193,975		112,062
Equity securities
Assets:
Investment securities available for sale	124,391		118,474
Equity securities | Fair Value, Measurements, Recurring [Member] | Total
Assets:
Investment securities available for sale	124,391		118,474
Equity securities | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investment securities available for sale	123,514		117,737
Equity securities | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2)
Assets:
Investment securities available for sale	877		737
Equity securities | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Assets:
Investment securities available for sale	0		0
U.S. Government securities
Assets:
Investment securities available for sale	14,970
U.S. Government securities | Fair Value, Measurements, Recurring [Member] | Total
Assets:
Investment securities available for sale	14,970		13,990
U.S. Government securities | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investment securities available for sale	0		0
U.S. Government securities | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2)
Assets:
Investment securities available for sale	14,970		13,990
U.S. Government securities | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Assets:
Investment securities available for sale	0		0
Corporate securities
Assets:
Investment securities available for sale	30,304
Corporate securities | Fair Value, Measurements, Recurring [Member] | Total
Assets:
Investment securities available for sale	30,304		29,923
Corporate securities | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investment securities available for sale	6,975		6,497
Corporate securities | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2)
Assets:
Investment securities available for sale	23,329		23,426
Corporate securities | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Assets:
Investment securities available for sale	0		0
U.S. mortgage backed securities
Assets:
Investment securities available for sale	219
U.S. mortgage backed securities | Fair Value, Measurements, Recurring [Member] | Total
Assets:
Investment securities available for sale	219		495
U.S. mortgage backed securities | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investment securities available for sale	0		0
U.S. mortgage backed securities | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2)
Assets:
Investment securities available for sale	219		495
U.S. mortgage backed securities | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Assets:
Investment securities available for sale	0		0
Commercial mortgage-backed securities
Assets:
Investment securities available for sale	6,705
Commercial mortgage-backed securities | Fair Value, Measurements, Recurring [Member] | Total
Assets:
Investment securities available for sale	6,705		6,822
Commercial mortgage-backed securities | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investment securities available for sale	0		0
Commercial mortgage-backed securities | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2)
Assets:
Investment securities available for sale	6,705		6,822
Commercial mortgage-backed securities | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Assets:
Investment securities available for sale	0		0
U.S. asset backed securities
Assets:
Investment securities available for sale	3,995
U.S. asset backed securities | Fair Value, Measurements, Recurring [Member] | Total
Assets:
Investment securities available for sale	3,995		2,081
U.S. asset backed securities | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investment securities available for sale	0		0
U.S. asset backed securities | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2)
Assets:
Investment securities available for sale	3,995		2,081
U.S. asset backed securities | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Assets:
Investment securities available for sale	0		0
Index-linked U.S. bonds
Assets:
Investment securities available for sale	252
Index-linked U.S. bonds | Fair Value, Measurements, Recurring [Member] | Total
Assets:
Investment securities available for sale	252		749
Commodity Index Linked Notes [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investment securities available for sale	0		0
Commodity Index Linked Notes [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2)
Assets:
Investment securities available for sale	252		749
Commodity Index Linked Notes [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Assets:
Investment securities available for sale	0		0
Fixed income securities
Assets:
Investment securities available for sale	56,445		54,060
Fixed income securities | Fair Value, Measurements, Recurring [Member] | Total
Assets:
Investment securities available for sale	56,445		54,060
Fixed income securities | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investment securities available for sale	6,975		6,497
Fixed income securities | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2)
Assets:
Investment securities available for sale	49,470		47,563
Fixed income securities | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Assets:
Investment securities available for sale	0		0
Warrants | Ladenburg Thalmann Financial Services [Member] | New Valley LLC [Member]
Liabilities:
Investment (in shares)				1,000,000
Investment	1,602		1,758
Change in fair value gain (loss)	$ (157)	$ (65)