Nature of Business and Financial Statement Presentation - Additional Information (Detail) $ / shares in Units, $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2020 $ / shares	Jun. 30, 2019 $ / shares	Mar. 31, 2019 $ / shares	Jun. 30, 2020 USD ($) JointVenture	Dec. 31, 2019 USD ($)
Nature Of Business And Financial Statement Presentation [Line Items]
Maximum exposure to losses associated with VIEs | $				$ 89.6	$ 114.0
Common share dividend declared per share | $ / shares	$ 0.20	$ 0.20	$ 0.20
Variable Interest Entity, Not Primary Beneficiary [Member]
Nature Of Business And Financial Statement Presentation [Line Items]
Number of unconsolidated joint ventures | JointVenture				2