Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Liquidation Basis of Accounting [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Mar. 31, 2016
LIABILITIES
Liquidating distributions payable	$ 1,856	$ 6,213
Fair Value, Measurements, Recurring [Member]
ASSETS
Total Assets	528,358	662,958
LIABILITIES
Liquidating distributions payable	1,856	6,213
Fair Value, Measurements, Recurring [Member] | Cash Equivalents [Member] | Money Market Funds [Member]
ASSETS
Total Assets	3,197	1,835
Fair Value, Measurements, Recurring [Member] | Marketable Securities [Member] | U.S. Treasury Bills [Member]
ASSETS
Total Assets	525,161	655,121
Fair Value, Measurements, Recurring [Member] | Marketable Securities [Member] | U.S. Government Agency Securities [Member]
ASSETS
Total Assets		6,002
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
ASSETS
Total Assets	3,197	1,835
LIABILITIES
Liquidating distributions payable	1,856	6,213
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Cash Equivalents [Member] | Money Market Funds [Member]
ASSETS
Total Assets	3,197	1,835
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
ASSETS
Total Assets	525,161	661,123
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Marketable Securities [Member] | U.S. Treasury Bills [Member]
ASSETS
Total Assets	$ 525,161	655,121
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Marketable Securities [Member] | U.S. Government Agency Securities [Member]
ASSETS
Total Assets		$ 6,002