Share-Based Payment Arrangements - Schedule of Option Activity Under Stock Option Plans (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Shares, Outstanding at Beginning	1,332,656
Number of Shares, Exercised	(32,618)
Number of Shares, Forfeited	(16,549)
Number of Shares, Expired	(113,447)
Number of Shares, Outstanding at Ending	1,170,042
Number of Shares, Exercisable at Ending	885,673
Weighted- Average Exercise Price, Outstanding at Beginning	$ 38.85
Weighted- Average Exercise Price, Exercised	$ 29.51
Weighted- Average Exercise Price, Forfeited	$ 38.26
Weighted- Average Exercise Price, Expired	$ 63.41
Weighted- Average Exercise Price, Outstanding at Ending	$ 36.74
Weighted- Average Exercise Price, Exercisable at Ending	$ 38.55
Weighted-Average Remaining Contractual Term, Outstanding at Ending Balance (in years)	4 years 4 months 24 days
Weighted-Average Remaining Contractual Term, Exercisable at Ending Balance (in years)	3 years 7 months 6 days
Aggregate Intrinsic Value, Outstanding at Ending	$ 799
Aggregate Intrinsic Value, Exercisable at Ending	$ 373