Millis Transfer Acquistion (Details) - USD ($)		3 Months Ended	9 Months Ended
	Aug. 26, 2019	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Business Combinations [Abstract]
Payments to Acquire Businesses, Net of Cash Acquired			$ 62,127,000	$ 0
Business Combination, Total Consideration	$ 156,200,000
Business Combination, Cash and Equity Transferred	62,877,000
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned	750,000
Accounts and Other Receivables, Net, Current	14,574,000
Other Assets, Current	1,696,000
Property, Plant and Equipment, Net	121,151,000
Other Assets, Noncurrent	802,000
Intangible Assets, Current	15,300,000
Goodwill, Acquired During Period	32,611,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	186,134,000
Accounts Payable and Accrued Liabilities	(30,381,000)
Self Insurance Reserve	(4,871,000)
Long-term Debt	(70,191,000)
Deferred Taxes	(17,814,000)
Noncash or Part Noncash Acquisition, Debt Assumed	$ 93,300,000
Debt, Long-term and Short-term, Combined Amount		$ 53,500,000	$ 53,500,000		$ 0.0
Aquired Business Percent of Assets		19.60%	19.60%
Acquired Business Percent of Revenue		10.60%	3.60%
Business Combination, Acquisition Related Costs		$ 400,000	$ 500,000