Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Effective change in income tax rate	0.60%
Discrete benefit from change in tax status of subsidiary from partnership to corporation	$ 6.9	$ 13.2
Income tax expense (benefit)	$ 0.1	$ (5.0)