Recent Accounting Pronouncements - Additional Information (Detail) - USD ($) $ in Millions		Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Recent Accounting Pronouncements [Line Items]
Operating lease assets		$ 83.4
Operating lease liabilities	[1],[2]	89.0
Retained earnings		$ 63.1		$ 14.2
ASU 2016-02 [Member]
Recent Accounting Pronouncements [Line Items]
Operating lease assets			$ 82.3
Operating lease liabilities			87.6
Retained earnings			$ 3.0

[1] Includes the current portion of $17.8 million for operating leases and $13.5 million for finance leases.

[2] There were no operating leases with options to extend lease terms that are reasonably certain of being exercised and the operating lease payments exclude $0.3 million of legally binding minimum lease payments for leases signed but not yet commenced.