Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Liquidation Basis of Accounting [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Mar. 31, 2018
Liabilities:
Liquidating distributions payable	$ 1,792	$ 1,825
Fair Value, Measurements, Recurring [Member]
Assets:
Total Assets	502,420	505,723
Liabilities:
Liquidating distributions payable	1,792	1,825
Fair Value, Measurements, Recurring [Member] | Cash Equivalents [Member] | Money Market Funds [Member]
Assets:
Total Assets	168	540
Fair Value, Measurements, Recurring [Member] | Marketable Securities [Member] | U.S. Treasury Bills [Member]
Assets:
Total Assets	502,252	505,183
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets:
Total Assets	168	540
Liabilities:
Liquidating distributions payable	1,792	1,825
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Cash Equivalents [Member] | Money Market Funds [Member]
Assets:
Total Assets	168	540
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Marketable Securities [Member] | U.S. Treasury Bills [Member]
Assets:
Total Assets		0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets:
Total Assets	502,252	505,183
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Marketable Securities [Member] | U.S. Treasury Bills [Member]
Assets:
Total Assets	$ 502,252	$ 505,183