Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Liquidation Basis of Accounting [Member] - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017
Liabilities:
Liquidating distributions payable	$ 1,825	$ 9,205
Fair Value, Measurements, Recurring [Member]
Assets:
Total Assets	505,723	524,561
Liabilities:
Liquidating distributions payable	1,825	9,205
Fair Value, Measurements, Recurring [Member] | Cash Equivalents [Member] | Money Market Funds [Member]
Assets:
Total Assets	540	2,109
Fair Value, Measurements, Recurring [Member] | Marketable Securities [Member] | U.S. Treasury Bills [Member]
Assets:
Total Assets	505,183	522,452
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets:
Total Assets	540	2,109
Liabilities:
Liquidating distributions payable	1,825	9,205
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Cash Equivalents [Member] | Money Market Funds [Member]
Assets:
Total Assets	540	2,109
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets:
Total Assets	505,183	522,452
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Marketable Securities [Member] | U.S. Treasury Bills [Member]
Assets:
Total Assets	$ 505,183	$ 522,452