Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Liquidation Basis of Accounting [Member] - USD ($) $ in Thousands	Mar. 31, 2017	Mar. 31, 2016
Liabilities:
Liquidating distributions payable	$ 9,205	$ 6,213
Fair Value, Measurements, Recurring [Member]
ASSETS
Total Assets	524,561	662,958
Liabilities:
Liquidating distributions payable	9,205	6,213
Fair Value, Measurements, Recurring [Member] | Cash Equivalents [Member] | Money Market Funds [Member]
ASSETS
Total Assets	2,109	1,835
Fair Value, Measurements, Recurring [Member] | Marketable Securities [Member] | U.S. Treasury Bills [Member]
ASSETS
Total Assets	522,452	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	2,109	1,835
Liabilities:
Liquidating distributions payable	9,205	6,213
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Cash Equivalents [Member] | Money Market Funds [Member]
ASSETS
Total Assets	2,109	1,835
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
ASSETS
Total Assets	522,452	661,123
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Marketable Securities [Member] | U.S. Treasury Bills [Member]
ASSETS
Total Assets	$ 522,452	655,121
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Marketable Securities [Member] | U.S. Government Agency Securities [Member]
ASSETS
Total Assets		$ 6,002