Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Mar. 31, 2015	Sep. 30, 2015	Jun. 30, 2015
Income Tax Disclosure [Line Items]
Income tax expense (benefit) adjustment	$ (3,000,000)
Kronos
Income Tax Disclosure [Line Items]
Income taxes on dividends received		$ 0
Deferred income tax asset valuation allowance		$ 2,300,000	$ 150,300,000