Earnings Per Share - Numbers of Shares Used in Earnings Per Share Computation (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Basic:
Weighted average common shares outstanding	41,899	42,609	42,877
Diluted:
Dilutive effect of stock appreciation rights, restricted stock, restricted stock units and shares held in a rabbi trust	548	205	48
Total weighted average diluted shares outstanding	42,447	42,814	42,925
Anti-dilutive shares excluded from the diluted earnings per share calculation	20	37	42