Balance Sheet Components - Additional Information (Detail) (USD $)
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3 Months Ended | 12 Months Ended | 176 Months Ended | |
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Mar. 31, 2014
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Mar. 31, 2013
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Dec. 31, 2013
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Mar. 31, 2014
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Collaboration Arrangement Disclosure [Abstract] | ||||
Depreciation expense | $ 488,000 | $ 453,000 | $ 9,399,000 | |
Outstanding obligations related to construction-in-progress | 3,000,000 | 1,800,000 | ||
Capitalized interest costs | $ (231,000) | $ (684,000) |