Earnings per Share - Schedule Of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income attributable to continuing operations	$ (32,984)	$ 32,066	$ 12,532	$ 14,413	$ 25,216	$ 25,486	$ 29,306	$ 12,683	$ 26,027	$ 92,691	$ 69,590
Preferred stock dividends									42	42	41
Income from continuing operations available to common equity									25,985	92,649	69,549
Dividends and undistributed earnings allocated to participating securities									(62)	(144)	(192)
Income from continuing operations available to common shareholders									25,923	92,505	69,357
Net (loss) income attributable to discontinued operations	$ 0	$ 0	$ 0	$ 0	$ (300)	$ (1,300)	$ 1,777	$ (932)	0	(755)	1,217
Preferred stock dividends									0	0	(1)
(Loss) income from discontinued operations available to common equity									0	(755)	1,216
Dividends and undistributed earnings allocated to participating securities									0	1	(3)
(Loss) income from discontinued operations available to common shareholders									$ 0	$ (754)	$ 1,213
Basic weighted-average shares outstanding									37,997	37,456	37,293
Stock options and other stock compensation									700	530	417
Diluted weighted-average shares outstanding									38,697	37,986	37,710
Antidilutive stock options									0	0	658
Earnings per share attributable to continuing operations:
Earnings per share attributable to continuing operations, basic (dollars per share)	$ (0.87)	$ 0.84	$ 0.33	$ 0.38	$ 0.67	$ 0.68	$ 0.78	$ 0.34	$ 0.68	$ 2.47	$ 1.86
Earnings per share attributable to continuing operations, diluted (dollars per share)	(0.87)	0.83	0.32	0.37	0.66	0.67	0.77	0.34	0.67	2.44	1.84
(Loss) earnings per share attributable to discontinued operations:
Earnings per share attributable to discontinued operations, basic (dollars per share)	0.00	0.00	0.00	0.00	(0.01)	(0.04)	0.05	(0.03)	0.00	(0.02)	0.03
Earnings per share attributable to discontinued operations, diluted (dollars per share)	$ 0.00	$ 0.00	$ 0.00	$ 0.00	$ (0.01)	$ (0.04)	$ 0.05	$ (0.03)	$ 0.00	$ (0.02)	$ 0.03