Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Liquidation Basis of Accounting [Member] - USD ($) $ in Thousands	Sep. 30, 2017	Mar. 31, 2017
Liabilities:
Liquidating distributions payable	$ 8,790	$ 9,205
Fair Value, Measurements, Recurring [Member]
Assets:
Total Assets	508,025	524,561
Liabilities:
Liquidating distributions payable	8,790	9,205
Fair Value, Measurements, Recurring [Member] | Cash Equivalents [Member] | Money Market Funds [Member]
Assets:
Total Assets	599	2,109
Fair Value, Measurements, Recurring [Member] | Marketable Securities [Member] | U.S. Treasury Bills [Member]
Assets:
Total Assets	507,426	522,452
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets:
Total Assets	599	2,109
Liabilities:
Liquidating distributions payable	8,790	9,205
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Cash Equivalents [Member] | Money Market Funds [Member]
Assets:
Total Assets	599	2,109
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets:
Total Assets	507,426	522,452
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Marketable Securities [Member] | U.S. Treasury Bills [Member]
Assets:
Total Assets	$ 507,426	$ 522,452