Commitments and Contingencies - Additional Information (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($)
Loss Contingencies [Line Items]
General Obligation Bonds Issued in 2012 and 2014	$ 6,000,000
Gain Contingency, Unrecorded Amount	142,000
CITIGROUP GLOBAL MARKETS [Member]
Loss Contingencies [Line Items]
Gain Contingency, Unrecorded Amount	285,000
Other Party [Member]
Loss Contingencies [Line Items]
Gain Contingency, Unrecorded Amount	$ 2,550