Share-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands					1 Months Ended	12 Months Ended
	Dec. 31, 2016	Nov. 03, 2016	Jun. 30, 2016	Jun. 09, 2016	May 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration date						May 10, 2021
Number of shares authorized	10,815,000					10,815,000			6,550,000
Number of additional shares authorized (in shares)				2,000,000	2,265,000
Maximum number of shares per employee (in shares)						2,000,000.0
Number of shares available for grant (in shares)	2,204,362					2,204,362
Grant-date fair value of options granted						$ 1,800	$ 5,100	$ 700
Weighted-average grant date fair value of options granted						$ 1.42	$ 6.49	$ 10.05
Cash received from exercise of stock options						$ 200	$ 200	$ 5,500
Fair value of options vested						10,400	1,700	5,700
Grant-date fair value of share-based awards granted						$ 3,700	18,400	24,000
Performance shares legally granted that have not met the grant-date requirements required by GAAP (in shares)		192,024				192,024
Total fair value of shares vested and settled						$ 7,900	$ 7,400	$ 900
Number of shares granted (in shares)						1,128,522	1,046,362	738,164
Number of Days Prior to Performance Period						20 days
Share-based Compensation						$ 6,568	$ 20,937	$ 14,533
Tax Benefit from Share-based Compensation Expense						2,500	$ 8,000	$ 5,500
Total unrecognized compensation for unvested stock options	$ 1,300					1,300
Total unrecognized compensation for unvested shares	$ 3,200					$ 3,200
Weighted average grant date fair value per share of RSUs granted						$ 3.28	$ 17.62	$ 32.46
Compensation benefit resulting from modifications							$ 1,300
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						3 years
Performance Percentage						0.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term in years						10 years
Award vesting period						4 years
Performance Percentage						200.00%
Former Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation benefit resulting from modifications						$ 1,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						3 years
Number of shares granted (in shares)	0
Weighted average period over which unrecognized share-based compensation is expected to be recognized						10 months 24 days
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period over which unrecognized share-based compensation is expected to be recognized						1 year 5 months
Restricted Stock Units [Member] | Former Chief Executive Officer And President [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted (in shares)						500,000
Restricted Stock Units [Member] | Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted (in shares)						175,438
Restricted Stock Units [Member] | Chief Executive Officer And Former Chief Executive Officer And President [Member] [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						3 years
Restricted Stock Units [Member] | Former Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs granted			125,000
Weighted average grant date fair value per share of RSUs granted			$ 2.85