Commitments and Contingencies - Narrative (Detail)	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Loss Contingencies [Line Items]
Rent expense	$ 16,800,000	$ 11,700,000	$ 13,900,000
Salary and incentive program severance multiplier	3
Self insurance deductible for workers compensation, per occurrence	$ 5,000,000.0
Self insurance deductible for general liability claims, per occurrence	1,000,000.0
Self insurance deductible for medical and dental coverage, per occurrence	400,000
Self insurance deductible for automobile liabilities, per occurrence	1,000,000.0
Workers' compensation self-insured risk reserve, short-term	15,900,000	14,800,000
Workers' compensation self-insured risk reserve, long-term		15,600,000
Self insured risk accruals	30,300,000	35,000,000
Receivable for medical and dental coverage	1,500,000	$ 19,000
Chief Executive Officer
Loss Contingencies [Line Items]
Annual salary	$ 665,000
Minimum
Loss Contingencies [Line Items]
Severance payment multiplier	0.75
Severance payment for the chance of control multiplier	1.5
Maximum
Loss Contingencies [Line Items]
Severance payment multiplier	1.0
Severance payment for the chance of control multiplier	2.0
Non-Cancelable Property and Equipment | Minimum
Loss Contingencies [Line Items]
Term of operating leases	12 months
Non-Cancelable Property and Equipment | Maximum
Loss Contingencies [Line Items]
Term of operating leases	60 months
Well Service Units and Equipment | Maximum
Loss Contingencies [Line Items]
Term of operating leases	99 years