Debt and Financing (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 1,078,100,000		$ 1,078,100,000
Premium/(Discount), Debt	(3,900,000)		(3,900,000)
Debt Issuance Cost	(14,000,000)		(14,000,000)
Book Value	1,060,200,000		1,060,200,000
Book Value, Current Maturities	(16,000,000)		(16,000,000)	$ (15,900,000)
Par Value, Excluding Current Maturities	1,062,100,000		1,062,100,000
Debt Instrument, Unamortized Discount (Premium), Net, Noncurrent Maturities	3,900,000		3,900,000
Book Value, Excluding Current Maturities	1,044,200,000		1,044,200,000	1,046,500,000
Cash and cash equivalents	184,900,000	$ 136,400,000	184,900,000	173,800,000	$ 171,100,000
Operating leases, future minimum payments, remainder of fiscal year	67,200,000		67,200,000
Operating leases, future minimum payments due	290,200,000		290,200,000
Acquisition of property and equipment	(19,800,000)	$ (21,300,000)
Carrying Amount [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value	1,060,200,000		1,060,200,000	1,062,400,000
Fair Value [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value	903,200,000		903,200,000	979,600,000
Term Loan
Debt Instrument [Line Items]
Long-term Debt, Gross	684,300,000		684,300,000
Premium/(Discount), Debt	(3,900,000)		(3,900,000)
Debt Issuance Cost	(11,700,000)		(11,700,000)
Book Value	668,700,000		668,700,000
Debt Instrument, Gross, Current Maturities	(7,000,000)		(7,000,000)
Premium/(Discount), Current Maturities	0		0
Deferred Finance Costs, Current, Net	0		0
Book Value, Current Maturities	$ (7,000,000)		$ (7,000,000)
Stated Interest Rate	8.00%		8.00%
Average Effective Interest Rate	8.20%		8.20%
Term Loan | Carrying Amount [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value	$ 668,700,000		$ 668,700,000	669,000,000
Term Loan | Fair Value [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value	555,000,000		555,000,000	594,600,000
Line of Credit [Member] | 2014 ABL Facility Credit Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	0		0
Premium/(Discount), Debt	0		0
Debt Issuance Cost	0		0
Book Value	0		0
Borrowing base	442,900,000		442,900,000
Line of credit facility, total cash and availability	81,500,000		81,500,000
Secured Second A&R CDA [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	44,000,000		44,000,000
Premium/(Discount), Debt	0		0
Debt Issuance Cost	(300,000)		(300,000)
Book Value	$ 43,700,000		$ 43,700,000
Average Effective Interest Rate	7.30%		7.30%
Stated Interest Rate, Minimum	3.30%
Stated Interest Rate, Maximum	18.30%
Unsecured Second A&R CD [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 73,200,000		$ 73,200,000
Premium/(Discount), Debt	0		0
Debt Issuance Cost	(400,000)		(400,000)
Book Value	$ 72,800,000		$ 72,800,000
Average Effective Interest Rate	7.30%		7.30%
Stated Interest Rate, Minimum	3.30%
Stated Interest Rate, Maximum	18.30%
Lease Financing Obligations [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 276,600,000		$ 276,600,000
Premium/(Discount), Debt	0		0
Debt Issuance Cost	(1,600,000)		(1,600,000)
Book Value	275,000,000		275,000,000
Debt Instrument, Gross, Current Maturities	(9,000,000)		(9,000,000)
Premium/(Discount), Current Maturities	0		0
Deferred Finance Costs, Current, Net	0		0
Book Value, Current Maturities	$ (9,000,000)		$ (9,000,000)
Average Effective Interest Rate	12.00%		12.00%
Stated Interest Rate, Minimum	9.00%
Stated Interest Rate, Maximum	18.20%
Lease Financing Obligations [Member] | Carrying Amount [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value	$ 275,000,000		$ 275,000,000	276,300,000
Lease Financing Obligations [Member] | Fair Value [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value	253,100,000		253,100,000	282,900,000
Letter of Credit [Member] | 2014 ABL Facility Credit Agreement [Member]
Debt Instrument [Line Items]
Letters of credit outstanding, amount	361,400,000		361,400,000
10 percent of Borrowing Base	44,300,000		44,300,000
10 percent of line cap	45,000,000		45,000,000
Other Debt Obligations [Member] | Carrying Amount [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value	116,500,000		116,500,000	117,100,000
Other Debt Obligations [Member] | Fair Value [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value	$ 95,100,000		$ 95,100,000	$ 102,100,000
Credit Agreement Amendment, September 2014 [Member]
Debt Instrument [Line Items]
Maximum Total Leverage Ratio, March 31, 2016	4.0
Maximum Total Leverage Ratio, June 30, 2016	3.75
Maximum Total Leverage Ratio, September 30, 2016	3.75
Maximum Total Leverage Ratio, December 31, 2016	3.5
Maximum Total Leverage Ratio, March 31, 2017	3.25
Maximum Total Leverage Ratio, June 30, 2017	3.25
Maximum Total Leverage Ratio, September 30, 2017	3.25
Maximum Total Leverage Ratio, December 31, 2017 and thereafter	3.00
Debt Instrument, Total Leverage Ratio			3.20
2014 ABL Facility Credit Agreement [Member]
Debt Instrument [Line Items]
Amount able to be drawn	$ 37,200,000.0
2014 ABL Facility Credit Agreement [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, total cash and availability	222,100,000.0		$ 222,100,000.0
Revenue Equipment [Member]
Debt Instrument [Line Items]
Operating lease commitment	$ 29,500,000		$ 29,500,000
Operating lease term	5 years
London Interbank Offered Rate (LIBOR) [Member] | Term Loan
Debt Instrument [Line Items]
Floor interest rate	1.00%		1.00%
Basis Spread On Variable Rate, Total Leverage Ratio Less Than 3.25	7.00%
Basis Spread On Variable Rate, Total Leverage Ratio Higher Than 3.25	7.25%
Debt Instrument, Total Leverage Ratio	3.25