Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	0 Months Ended	3 Months Ended			8 Months Ended	9 Months Ended
	Apr. 30, 2013	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2013
Accounting Policies [Abstract]
Income from continuing operations		$ 9,776		$ 6,550		$ 28,417	$ 53,138
Loss from discontinued operations, net of income tax provision				68			7,102
Loss (gain) on disposal of discontinued operations	(800)		5,600	11	4,800		(783)
Net income		$ 9,776		$ 6,471		$ 28,417	$ 46,819
Weighted average common shares outstanding		33,115		32,262		32,743	32,344
Stock options		228		295		290	204
Denominator for diluted earnings per share		33,343		32,557		33,033	32,548
Earnings per share - continuing operations:
Basic - as reported		$ 0.30		$ 0.20		$ 0.87	$ 1.64
Diluted - as reported		$ 0.29		$ 0.20		$ 0.86	$ 1.63
Loss per share - discontinued operations
Basic - as reported							$ (0.20)
Diluted - as reported							$ (0.19)
Earnings per share - net income:
Basic - as reported		$ 0.30		$ 0.20		$ 0.87	$ 1.45
Diluted - as reported		$ 0.29		$ 0.20		$ 0.86	$ 1.44