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		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 15, 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 (in shares)	1,634	2,057	1,798	2,045
Common stock related to employee equity awards
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 (in shares)	7	99	3	95
4.75% convertible subordinated notes
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 (in shares)	1,627	1,958	1,795	1,950
Convertible debt interest rate (in shares)	4.75%	4.75%	4.75%	4.75%	4.75%