Earnings Per Share - Summary of Weighted-Average Outstanding Share-Based Awards Excluded from Computation of Diluted 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
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total shares excluded from diluted earnings per share	1,779	1,182	1,581	1,112
Performance Conditions [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total shares excluded from diluted earnings per share	191	52	143	33
Share-Based Awards [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total shares excluded from diluted earnings per share	1,588	1,130	1,438	1,079