Earnings Per Share - Anti-dilutive Potential Shares of Common Stock Excluded from Computation of Earnings Per Share (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive potential shares of common stock excluded from computation of earnings per share, amount	93	3,552
Common stock related to employee equity awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive potential shares of common stock excluded from computation of earnings per share, amount	93	1,583
4.75% Convertible Subordinated Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive potential shares of common stock excluded from computation of earnings per share, amount	0	1,969
Interest rate (percent)		4.75%