Condensed Consolidating Financial Information - Guarantor Subsidiaries - Condensed Consolidating Statements of Operations (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Condensed Income Statements, Captions [Line Items]
Operating revenues, net		$ 158,093	$ 214,733	$ 489,245	$ 617,477
Expenses:
Direct expenses		144,938	182,064	449,909	520,099
Selling, general and administrative expenses		13,381	11,575	36,832	34,859
Total operating expenses		158,319	193,639	486,741	554,958
Loss (gain) on disposal of assets, net		85	(165)	(3,854)	(238)
Equity in loss of unconsolidated affiliate		198	75	274	249
Operating income		(509)	21,184	6,084	62,508
Interest expense		7,719	7,366	22,792	21,691
Other income, net		(462)	(472)	(1,571)	(1,501)
Total expenses		7,257	6,894	21,221	20,190
(Loss) earnings before income taxes		(7,766)	14,290	(15,137)	42,318
Income tax (benefit) expense		(2,799)	6,621	(5,515)	17,832
Net (loss) earnings		(4,967)	7,669	(9,622)	24,486
Parent Company Only (issuer) [Member]
Condensed Income Statements, Captions [Line Items]
Operating revenues, net		79,532	124,505	260,766	368,202
Expenses:
Direct expenses		83,188	111,876	264,761	321,841
Selling, general and administrative expenses		10,639	9,219	28,914	27,198
Total operating expenses		93,827	121,095	293,675	349,039
Loss (gain) on disposal of assets, net		85	(165)	(3,854)	(238)
Equity in loss of unconsolidated affiliate		198	75	274	249
Operating income		(14,578)	3,500	(29,329)	19,152
Equity in net income of consolidated subsidiaries		(8,372)	(10,682)	(20,462)	(26,044)
Interest expense		7,716	7,274	22,762	21,599
Other income, net		(812)	(474)	(2,415)	(1,508)
Total expenses		(1,468)	(3,882)	(115)	(5,953)
(Loss) earnings before income taxes		(13,110)	7,382	(29,214)	25,105
Income tax (benefit) expense		(8,143)	(287)	(19,592)	619
Net (loss) earnings		(4,967)	7,669	(9,622)	24,486
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Operating revenues, net	[1]	78,561	90,228	228,479	249,275
Expenses:
Direct expenses	[1]	61,750	70,192	185,148	198,271
Selling, general and administrative expenses	[1]	3,092	2,356	8,766	7,661
Total operating expenses	[1]	64,842	72,548	193,914	205,932
Operating income	[1]	13,719	17,680	34,565	43,343
Interest expense	[1]	3	92	30	92
Other income, net	[1]		(2)	(4)	(6)
Total expenses	[1]	3	90	26	86
(Loss) earnings before income taxes	[1]	13,716	17,590	34,539	43,257
Income tax (benefit) expense	[1]	5,344	6,908	14,077	17,213
Net (loss) earnings	[1]	8,372	10,682	20,462	26,044
Eliminations [Member]
Expenses:
Direct expenses			(4)		(13)
Selling, general and administrative expenses		(350)		(848)
Total operating expenses		(350)	(4)	(848)	(13)
Operating income		350	4	848	13
Equity in net income of consolidated subsidiaries		8,372	10,682	20,462	26,044
Other income, net		350	4	848	13
Total expenses		8,722	10,686	21,310	26,057
(Loss) earnings before income taxes		(8,372)	(10,682)	(20,462)	(26,044)
Net (loss) earnings		$ (8,372)	$ (10,682)	$ (20,462)	$ (26,044)

[1] Foreign subsidiaries represent minor subsidiaries and are included in the guarantor subsidiaries' amounts.