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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32
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1/1/2011 - 3/31/2011
USD ($)
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1/1/2010 - 3/31/2010
USD ($)
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32
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-Number 157
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
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