Subsequent Events (Details) - USD ($)						9 Months Ended	12 Months Ended
	Nov. 05, 2019	Nov. 04, 2019	Sep. 01, 2019	Aug. 02, 2019	Sep. 01, 2018	Sep. 30, 2019	Dec. 31, 2017	Oct. 21, 2019	Aug. 20, 2019	Jul. 31, 2019	Feb. 28, 2019	Dec. 31, 2018	Jun. 30, 2018	Jul. 21, 2017
Subsequent Event [Line Items]
Long-term Debt						$ 195,016,000						$ 168,767,000
Insurance Premium Financing Agreement										$ 20,700,000			$ 17,800,000
Insurance Premium Financing Agreement, Periodic Payment			$ 2,400,000		$ 2,000,000
Insurance Premium Financing Agreement, Interest Rate			5.25%										4.75%
Elliott Management Corporation [Member]
Subsequent Event [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity						$ 40,400,000					$ 61,100,000
Letters of Credit Outstanding, Amount				$ 20,000,000					$ 30,000,000.0
Third Lien Credit Agreement [Member] | Subsequent Event
Subsequent Event [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 20,000,000
London Interbank Offered Rate (LIBOR) [Member] | ABL Credit Agreement [Member]
Subsequent Event [Line Items]
Debt instrument variable rate margin (as a percentage)				7.50%
London Interbank Offered Rate (LIBOR) [Member] | Third Lien Credit Agreement [Member] | Subsequent Event
Subsequent Event [Line Items]
Debt instrument variable rate margin (as a percentage)	7.50%
Base Rate | Third Lien Credit Agreement [Member] | Subsequent Event
Subsequent Event [Line Items]
Debt instrument variable rate margin (as a percentage)	6.50%
Roadrunner Intermodal Services [Member] | Subsequent Event
Subsequent Event [Line Items]
Proceeds from Divestiture of Businesses		$ 51,250,000
Letter of Credit [Member] | ABL Facility [Member]
Subsequent Event [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity														$ 30,000,000
Letter of Credit [Member] | ABL Facility [Member] | Subsequent Event
Subsequent Event [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity								$ 45,000,000
Maximum | London Interbank Offered Rate (LIBOR) [Member] | ABL Facility [Member]
Subsequent Event [Line Items]
Debt instrument variable rate margin (as a percentage)						2.25%
Maximum | Base Rate | ABL Facility [Member]
Subsequent Event [Line Items]
Debt instrument variable rate margin (as a percentage)							1.25%
Maximum | Letter of Credit [Member] | Junior Lien Debt [Member] | Subsequent Event
Subsequent Event [Line Items]
Long-term Debt								$ 100,000,000