Overview and Basis of Presentation - Additional Information (Detail) - Subsequent Event [Member] $ / shares in Units, $ in Millions	1 Months Ended
	Apr. 30, 2017 USD ($) $ / shares shares
Liquidity [Line Items]
Number of shares issued from public offering | shares	5,808,080
Net proceeds from public offering | $	$ 270.2
Public Offering [Member]
Liquidity [Line Items]
Number of shares issued from public offering | shares	5,050,505
Offering price per share | $ / shares	$ 49.50
Net proceeds from public offering | $	$ 235.0
Over-Allotment Option [Member]
Liquidity [Line Items]
Number of shares issued from public offering | shares	757,575
Net proceeds from public offering | $	$ 35.2