Stock-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Number of Shares
Options outstanding at Beginning of Year	185	304	345
Grants	0	0	0
Exercised	0	0	(1)
Forfeited or expired	0	119	40
Options outstanding at End of Year	185	185	304	345
Exercisable options outstanding	185	185	304
Weighted Average Exercise Price
Options outstanding at Beginning of Year	$ 24.86	$ 28.11	$ 27.98
Grants	0	0	0
Exercised	0.00	0.00	22.28
Forfeited or expired	0.00	33.15	27.27
Options outstanding at End of Year	24.86	24.86	28.11	$ 27.98
Exercisable options outstanding	$ 24.86	$ 24.86	$ 28.11
ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsinPeriodWeightedAverageRemainingContractualTerm(Years)			0 years
Share Based Compensation Arrangement By Share Based Payment Award Nonvested Options Granted In Period Weighted Average Remaining Contractual Term (Years)	0 years	0 years	0 years
Weighted Average Remaining Contractual Term (years)
Options outstanding at Beginning of Year	3 years 1 month 12 days	4 years 1 month 12 days	3 years 2 months 12 days	3 years 8 months 12 days
Options outstanding at End of Year	3 years 1 month 12 days	4 years 1 month 12 days	3 years 2 months 12 days	3 years 8 months 12 days
Exercisable options outstanding	3 years 1 month 12 days	4 years 1 month 12 days	3 years 2 months 12 days
Aggregate Intrinsic Value
Options outstanding at Beginning of Year	$ 0	$ 0	$ 59
Grants	0	0	0
Exercised	0	0	2
Options outstanding at End of Year	0	0	0	$ 59
Exercisable options outstanding	$ 0	$ 0	$ 0