Share-Based Compensation (Detail) - Nonqualified Stock Option Transactions $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding beginning balance | shares	1,153
Expired | shares	(397)
Options outstanding ending balance | shares	756
Exercisable at the end of the year | shares	756
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price [Abstract]
Options outstanding beginning balance (in dollars per share) | $ / shares	$ 32.93
Expired (in dollars per share) | $ / shares	33.66
Options outstanding ending balance (in dollars per share) | $ / shares	32.55
Exercisable at the end of the year (in dollars per share) | $ / shares	$ 32.55
Weighted average remaining contractual term of options outstanding ending balance (in years)	1 year 3 months 27 days	[1]
Weighted average remaining contractual term of options exercisable at the end of the year (in years)	1 year 3 months 27 days	[1]
Aggregate intrinsic value of options outstanding at the end of the year | $	$ 273	[2]
Aggregate intrinsic value of options exercisable at the end of the year | $	$ 273	[2]

[1] Represents the average remaining contractual life in years.

[2] Aggregate intrinsic value represents the total pre-tax intrinsic value that would have been received by the option holders if they had exercised their options on December 31, 2015. Intrinsic value equals the difference between the Company's average of the high and low stock price on the last trading day of the year and the option exercise price, multiplied by the number of shares. This amount will fluctuate with changes in the fair value of the Company's common stock.