Stockholders' Equity and EPS - Common Shares Excluded from Diluted EPS Calculation as They Were Deemed to be Anti-Dilutive (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from diluted earnings per share calculation	4	21
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from diluted earnings per share calculation	4	0
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from diluted earnings per share calculation	0	21