Investments and Fair Value Measurements (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Nov. 30, 2012	May 22, 2013	Nov. 04, 2011
Assets:
Investment securities available for sale	$ 346,043,000	$ 172,534,000
Liabilities:
Fair value of derivatives embedded within covertible debt	884,000	19,128,000
Nonrecurring nonfinancial assets subject to fair value measurements	0	0
Convertible Debt [Member]
Liabilities:
Fair value of derivatives embedded within covertible debt	169,386,000	112,062,000
Convertible Debt [Member] | 7.5% Senior Convertible Debentures [Member]
Liabilities:
Interest rate effective percentage			7.50%
Ladenburg Thalmann Financial Services [Member]
Liabilities:
Investment in equity securities, shares held				240,000
Equity Securities [Member]
Assets:
Investment securities available for sale	154,192,000	118,474,000
Mutual Funds Invested in Fixed Income Securities [Member]
Assets:
Investment securities available for sale	59,826,000
US Government Agencies Debt Securities [Member]
Assets:
Investment securities available for sale	35,446,000
Corporate Debt Securities [Member]
Assets:
Investment securities available for sale	56,248,000
US Government and Government Agencies and Authorities [Member]
Assets:
Investment securities available for sale	4,770,000
Commercial Mortgage Backed Securities [Member]
Assets:
Investment securities available for sale	16,508,000
Asset-backed Securities [Member]
Assets:
Investment securities available for sale	16,955,000
Fixed Income Securities [Member]
Assets:
Investment securities available for sale	132,025,000
Warrant [Member] | Ladenburg Thalmann Financial Services [Member] | New Valley LLC [Member]
Liabilities:
Investment in equity securities, shares held					1,000,000
Investment owned at cost	2,342,000	1,758,000
Changes in fair value, gain (loss)	584,000	1,041,000
Fair Value, Measurements, Recurring [Member]
Assets:
Money market funds	205,180,000	130,733,000
Certificates of deposit	3,462,000	2,961,000
Bonds	4,868,000	5,337,000
Warrants	2,342,000	1,935,000
Total	561,895,000	313,500,000
Liabilities:
Fair value of derivatives embedded within convertible debt	169,386,000	112,062,000
Fair Value, Measurements, Recurring [Member] | Equity Securities [Member]
Assets:
Investment securities available for sale	154,192,000	118,474,000
Fair Value, Measurements, Recurring [Member] | Mutual Funds Invested in Fixed Income Securities [Member]
Assets:
Investment securities available for sale	59,826,000
Fair Value, Measurements, Recurring [Member] | US Government Agencies Debt Securities [Member]
Assets:
Investment securities available for sale	35,446,000	13,990,000
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member]
Assets:
Investment securities available for sale	56,248,000	29,923,000
Fair Value, Measurements, Recurring [Member] | US Government and Government Agencies and Authorities [Member]
Assets:
Investment securities available for sale	4,770,000	495,000
Fair Value, Measurements, Recurring [Member] | Commercial Mortgage Backed Securities [Member]
Assets:
Investment securities available for sale	16,508,000	6,822,000
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]
Assets:
Investment securities available for sale	16,955,000	2,081,000
Fair Value, Measurements, Recurring [Member] | Commodity Index Linked Notes [Member]
Assets:
Investment securities available for sale	2,098,000	749,000
Fair Value, Measurements, Recurring [Member] | Fixed Income Securities [Member]
Assets:
Investment securities available for sale	132,025,000	54,060,000
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Money market funds	205,180,000	130,733,000
Certificates of deposit	0	0
Bonds	4,868,000	5,337,000
Warrants	0	0
Total	430,937,000	260,304,000
Liabilities:
Fair value of derivatives embedded within convertible debt	0	0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity Securities [Member]
Assets:
Investment securities available for sale	153,666,000	117,737,000
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mutual Funds Invested in Fixed Income Securities [Member]
Assets:
Investment securities available for sale	59,826,000
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | US Government Agencies Debt Securities [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate Debt Securities [Member]
Assets:
Investment securities available for sale	7,397,000	6,497,000
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | US Government and Government Agencies and Authorities [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial Mortgage Backed Securities [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Asset-backed Securities [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Commodity Index Linked Notes [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed Income Securities [Member]
Assets:
Investment securities available for sale	7,397,000	6,497,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2)
Assets:
Money market funds	0	0
Certificates of deposit	3,462,000	2,961,000
Bonds	0	0
Warrants	0	0
Total	128,616,000	51,261,000
Liabilities:
Fair value of derivatives embedded within convertible debt	0	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) | Equity Securities [Member]
Assets:
Investment securities available for sale	526,000	737,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) | Mutual Funds Invested in Fixed Income Securities [Member]
Assets:
Investment securities available for sale	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) | US Government Agencies Debt Securities [Member]
Assets:
Investment securities available for sale	35,446,000	13,990,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) | Corporate Debt Securities [Member]
Assets:
Investment securities available for sale	48,851,000	23,426,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) | US Government and Government Agencies and Authorities [Member]
Assets:
Investment securities available for sale	4,770,000	495,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) | Commercial Mortgage Backed Securities [Member]
Assets:
Investment securities available for sale	16,508,000	6,822,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) | Asset-backed Securities [Member]
Assets:
Investment securities available for sale	16,955,000	2,081,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) | Commodity Index Linked Notes [Member]
Assets:
Investment securities available for sale	2,098,000	749,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) | Fixed Income Securities [Member]
Assets:
Investment securities available for sale	124,628,000	47,563,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Assets:
Money market funds	0	0
Certificates of deposit	0	0
Bonds	0	0
Warrants	2,342,000	1,935,000
Total	2,342,000	1,935,000
Liabilities:
Fair value of derivatives embedded within convertible debt	169,386,000	112,062,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) | Equity Securities [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) | Mutual Funds Invested in Fixed Income Securities [Member]
Assets:
Investment securities available for sale	0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) | US Government Agencies Debt Securities [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) | Corporate Debt Securities [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) | US Government and Government Agencies and Authorities [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) | Commercial Mortgage Backed Securities [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) | Asset-backed Securities [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) | Commodity Index Linked Notes [Member]
Assets:
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) | Fixed Income Securities [Member]
Assets:
Investment securities available for sale	$ 0	$ 0