Long-Term Debt and Notes Payable - Additional Information (Detail)	1 Months Ended		6 Months Ended	9 Months Ended
	May 31, 2016 USD ($) BoardofDirector	Apr. 30, 2016 USD ($) Subsidiary	Jun. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Oct. 27, 2016 USD ($)	Dec. 31, 2015 USD ($)
Line of Credit Facility [Line Items]
Long-term debt				$ 45,592,000			$ 55,000,000
Long-term debt, current				12,783,000			33,000,000
Interest cost				4,319,000	$ 1,946,000
Debt instrument, maturity date			Apr. 01, 2017
Notes payable			$ 1,468,000	$ 1,010,000
Debt instrument, payment terms				Payments are due monthly through April 1, 2017
Debt instrument, frequency of periodic payment				monthly
Debt instrument, effective interest rate			0.75%
Unsecured Promissory Notes
Line of Credit Facility [Line Items]
Debt instrument, maturity date	Apr. 01, 2019
Proceeds from issuance of notes	$ 25,000,000
Debt instrument, payable number | BoardofDirector	2
Debt instrument, interest rate	7.00%
Amended Credit Agreement
Line of Credit Facility [Line Items]
Long-term debt		$ 65,000,000		$ 58,934,000
Long-term debt, current				12,783,000
Long-term debt, long term				46,151,000
Debt issuance costs				$ 559,000
Line of credit, weighted average interest rate				6.225%
Revolving Line of credit, replaced amount		90,000,000
Standby letters of credit		15,000,000
Minimum quarterly repayments, thereafter		3,250,000
Required minimum cash balance to maintain from August 2016 until March 2017		40,000,000
Required minimum cash balance to maintain from April 2017 until December 2017		30,000,000
Required minimum cash balance to maintain thereafter December 2017		$ 25,000,000
Number of operating subsidiaries | Subsidiary		2
Debt instrument, maturity date		Dec. 31, 2018
Amended Credit Agreement | Quarter Four, 2016
Line of Credit Facility [Line Items]
Minimum quarterly repayments, remainder		$ 3,033,000
Amended Credit Agreement | Subsequent Event
Line of Credit Facility [Line Items]
Long-term debt						$ 55,901,000
Amended Credit Agreement | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Debt instrument, percentage points added to the reference rate		7.00%
Old Revolving Credit Facility
Line of Credit Facility [Line Items]
Long-term debt							88,000,000
Long-term debt, current							33,000,000
Long-term debt, long term							$ 55,000,000
Line of credit, weighted average interest rate							4.664%
Standby Letters of Credit
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity				$ 11,980,000			$ 8,875,000
Property, Plant and Equipment
Line of Credit Facility [Line Items]
Interest cost capitalized				$ 80,000	$ 1,355,000