Weighted Average Common Shares - Summary of Weighted Average Numbers of Common Shares Used to Compute Basic and Diluted Net Income Per Share (Detail) - shares shares in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2019	[1]	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Basic common shares outstanding	70,105		69,668	69,972	69,443
Common stock equivalents			1,894	1,810	1,796
Diluted common shares outstanding	70,105		71,562	71,782	71,239

[1] Due to the fact that we reported a loss from continuing operations for the quarter ended June 30, 2019, potential common stock equivalents are excluded from diluted common shares outstanding. Per FASB ASC Topic 260 – Earnings Per Share, an entity that reports discontinued operations shall use income or loss from continuing operations as the benchmark for calculating diluted common shares outstanding, and as such, we have zero common stock equivalents since these shares would have an anti-dilutive effect on our net loss per share for the quarter ended June 30, 2019