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Net Income per Share (Narrative) (Detail) - USD ($) $ in Thousands, shares in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Nov. 22, 2016	Nov. 20, 2015
Restricted Stock [Member]
Debt Instrument [Line Items]
Antidilutive securities excluded from computation of earnings per share (in Shares)	0.1	0.4
Option on Securities [Member]
Debt Instrument [Line Items]
Antidilutive securities excluded from computation of earnings per share (in Shares)	12.6	7.8
December 2021 Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				2.75%
Convertible notes	$ 12,402		$ 16,950	$ 150,000	$ 150,000