v2.4.0.8

Subsequent Events - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified | 1 Months Ended | 9 Months Ended | 12 Months Ended |  | 1 Months Ended | 0 Months Ended | 1 Months Ended | 12 Months Ended | 9 Months Ended | 0 Months Ended | 1 Months Ended | 0 Months Ended | 4 Months Ended | 1 Months Ended | 0 Months Ended | 1 Months Ended | 2 Months Ended | 0 Months Ended | 1 Months Ended | 0 Months Ended
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Jul. 26, 2013 | Sep. 30, 2013 | Sep. 30, 2012 | Dec. 31, 2012 | Dec. 31, 2011 | Aug. 13, 2013 | Jan. 20, 2012 Ziopharm [Member] | Feb. 07, 2011 Ziopharm [Member] | Jan. 06, 2011 Ziopharm [Member] | Mar. 15, 2013 AquaBounty [Member] | Feb. 28, 2013 AquaBounty [Member] | Jan. 31, 2013 AquaBounty [Member] | Dec. 31, 2012 AquaBounty [Member] | Sep. 30, 2013 Series F Redeemable Convertible Preferred Stock [Member] | Feb. 14, 2013 AquaBounty ECC [Member] | Mar. 31, 2013 AmpliPhi ECC [Member] Upfront and Milestone Payments [Member] Upfront [Member] | Mar. 31, 2013 Genopaver ECC [Member] Upfront and Milestone Payments [Member] Upfront [Member] | Apr. 27, 2013 Soligenix ECC [Member] Upfront and Milestone Payments [Member] Upfront [Member] | Jul. 26, 2013 Subsequent Event [Member] | Apr. 30, 2013 Subsequent Event [Member] | Oct. 31, 2013 Subsequent Event [Member] Fibrocell Science [Member] | Oct. 29, 2013 Subsequent Event [Member] Ziopharm [Member] | Mar. 15, 2013 Subsequent Event [Member] AquaBounty [Member] | Feb. 28, 2013 Subsequent Event [Member] AquaBounty [Member] | Jan. 31, 2013 Subsequent Event [Member] AquaBounty [Member] | Apr. 30, 2013 Subsequent Event [Member] Series F Redeemable Convertible Preferred Stock [Member] | Apr. 30, 2013 Subsequent Event [Member] Series F Redeemable Convertible Preferred Stock [Member] Shareholder | Feb. 14, 2013 Subsequent Event [Member] AquaBounty ECC [Member] | Mar. 31, 2013 Subsequent Event [Member] AmpliPhi ECC [Member] Upfront and Milestone Payments [Member] Upfront [Member] | Mar. 31, 2013 Subsequent Event [Member] Genopaver ECC [Member] Upfront and Milestone Payments [Member] Upfront [Member] | Apr. 27, 2013 Subsequent Event [Member] Soligenix ECC [Member] Upfront and Milestone Payments [Member] Upfront [Member]
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount drawn on promissory note |  | $ 300 |  | $ 200 |  |  |  |  |  |  | $ 100 | $ 200 | $ 200 |  |  |  |  |  |  |  |  |  |  | $ 100 | $ 200 |  |  |  |  |  |
Royalty rate as a percentage of gross profit |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 16.66% |  |  |  |  |  |  |  |  |  |  |  |  | 16.66% |  |  |
Proceeds from issuance of redeemable convertible preferred shares |  |  |  |  |  |  |  |  |  |  |  |  |  | 150,000 |  |  |  |  |  |  |  |  |  |  |  | 150,000 |  |  |  |  |
Payment of stock issuance costs |  | 3,148 | 11 | 16 | 2,675 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,100 | 1,800 |  |  |  |
Redeemable convertible preferred stock, stated value |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 7.88 |  |  |  |  |
Dividend rate per annum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6.00% |  |  |  |  |
Common stock, authorized |  | 200,000,000 |  | 160,000,000 | 155,000,000 | 200,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  | 185,000,000 |  |  |  |  |  |  |  |  |  |  |
Number of shares acquired |  |  |  |  |  |  |  |  |  | 18,714,814 |  |  |  |  |  |  |  |  |  |  |  |  | 18,714,814 |  |  |  |  |  |  |  |
Amount from private subscription offering |  |  |  |  |  |  |  |  |  | 4,907 |  |  |  |  |  |  |  |  |  |  |  |  | 4,907 |  |  |  |  |  |  |  |
Aggregate percentage of ownership |  |  |  |  |  |  |  |  |  | 53.82% |  |  |  |  |  |  |  |  |  |  |  |  | 53.82% |  |  |  |  |  |  |  |
Promissory note repaid |  | 500 | 34 | 34 | 300 |  |  |  |  | 500 |  |  |  |  |  |  |  |  |  |  |  |  | 500 |  |  |  |  |  |  |  |
Collaborative arrangement consideration received, shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 24,000,000 |  | 1,034,483 |  |  |  |  |  |  |  |  |  |  | 24,000,000 |  | 1,034,483
Collaborative arrangement consideration received, value |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,400 | 3,000 | 1,331 |  |  |  |  |  |  |  |  |  |  |  | 3,000 |
Decrease In Equity Securities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ (32,123) |  |  |  |  |  |  |  |  |  |  |
Shareholders approved a reverse stock split description | 1-for-1.75 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1-for-1.75 |  |  |  |  |  |  |  |  |  |  |  |
Shares of common stock purchased from collaborative partners |  |  |  |  |  |  | 1,923,075 | 1,910,000 | 2,426,235 |  |  |  |  |  |  |  |  |  |  |  | 2,439,024 | 2,857,143 |  |  |  |  |  |  |  |  |
Price per share |  |  |  |  |  |  | $ 5.20 | $ 5.75 | $ 4.80 |  |  |  |  |  |  |  |  |  |  |  | $ 4.10 | $ 3.50 |  |  |  |  |  |  |  |  |

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