Note 13 - Derivative Instruments	12 Months Ended
Dec. 31, 2017
Notes to Financial Statements
Derivative Instruments and Hedging Activities Disclosure [Text Block]	13. DERIVATIVE INSTRUMENTS We engage in activities that expose us to market risks, including the effects of changes in fuel prices and in interest rates. Financial exposures are evaluate d as an integral part of our risk management program, which seeks, from time-to-time, to reduce the potentially adverse effects that the volatility of fuel markets and interest rate risk may have on operating results. In an effort to seek to reduce the variability of the ultimate cash flows associated with fluctuations in diesel fuel prices, we periodically enter into various derivative instruments, including forward futures swap contracts. Specifically, we enter into hedging contracts with respect to ultra-low sulfur diesel ( "ULSD "). Under these contracts, we pay a fixed rate per gallon of ULSD and receive the monthly average price of Gulf Coast ULSD. The retrospective and prospective regression analyses provided that changes in the prices of diesel fuel and ULSD were deemed to be highly effective based on the relevant authoritative guidance except for a small portion of our hedging contracts, which we determined to be ineffective on a prospective basis in 2015. Consequently, we recognized a reduction in fuel expense of $1.4 million in 2015 to mark the related liability to market. At December 31, 2017 and 2016, there were no remaining ineffective fuel hedge contracts and, thus, all remaining fuel hedge contracts continue to qualify as cash flow hedges. We do not engage in speculative transactions, nor do we hold or issue financial instruments for trading purposes . Effective December 31, 2017, we adopted ASU 2017 - 12, which eliminates the requirement to separately measure and report hedge ineffectiveness. For the years ended 2017, 2016, and 2015, no hedge ineffectiveness has been recorded, thus no adjustments were required . In August 2015, we entered into an interest rate swap agreement with a notional amount of $28.0 million, which was designated as a hedge against the variability in future interest payments due on the debt associated with the purchase of our corporate headquarters. The terms of the swap agreement effectively convert the variable rate interest payments on this note to a fixed rate of 4.2% through maturity on August 1, 2035 . In 2016, we also entered into several interest rate swaps, which were designated to hedge against the variability in future interest rate payments due on rent associated with the purchase of certain trailers. Because the critical terms of the swap and hedged item coincide, in accordance with the requirements of ASC 815, the change in the fair value of the derivative is expected to exactly offset changes in the expected cash flows due to fluctuations in the LIBOR rate over the term of the debt instrument, and therefore no ongoing assessment of effectiveness is required. The fair value of the swap agreements that were in effect at December 31, 2017 and 2016, of approximately $0.4 million and $0.7 million, respectively, is included in other assets and other liabilities, as appropriate, in the consolidated balance sheet, and is included in accumulated other comprehensive income (loss), net of tax. Additionally, $0.4 million and $0.6 million was reclassified from accumulated other comprehensive income (loss) into our results of operations as additional interest expense for the year ended December 31, 2017 and 2016, respectively, related to changes in interest rates during such periods. Based on the amounts in accumulated other comprehensive income (loss) as of December 31, 2017, we expect to reclassify losses of approximately $0.2 million, net of tax, on derivative instruments from accumulated other comprehensive income (loss) into our results of operations during the next twelve months due to changes in interest rates. The amounts actually realized will depend on the fair values as of the date of settlement. We recognize all derivative instruments at fair value on our consolidated balance sheets. Our derivati ve instruments are designated as cash flow hedges, thus the gain or loss on the derivatives is reported as a component of accumulated other comprehensive income (loss) and will be reclassified into earnings in the same period during which the hedged transaction affects earnings. The change in fair value of the hedge offsets the change in fair value of the hedged item . At December 31, 2017 , we had fuel hedge contracts on approximately 7.6 million gallons of diesel to be purchased in 2018, or approximately 16.1% of our projected annual 2018 fuel requirements. The fair value of the contracts that were in effect at December 31, 2017 and 2016, of approximately $0.8 million and $3.6 million, respectively, are included in other assets and other liabilities, respectively, in the consolidated balance sheet, and are included in accumulated other comprehensive income (loss), net of tax . Changes in the fair values of these instruments can vary dramatically based on changes in the underlying commodity prices. For example, during 2017, market "spot" prices for ULSD peaked at a high of approximately $1.97 per gallon and hit a low price of approximately $1.33 per gallon. During 2016, market spot prices ranged from a high of $1.66 per gallon to a low of $0.83 per gallon. Market price changes can be driven by factors such as supply and demand, inventory levels, weather events, refinery capacity, political agendas, the value of the U.S. dollar, geopolitical events, and general economic conditions, among other items. Additionally, $4.1 million, $16.7 million, and $15.3 million were reclassified from accumulated other comprehensive income (loss) into our results of operations for the years ended December 31, 2017, 2016, and 2015, respectively, as additional fuel expense for 2017, 2016, and 2015, related to losses on fuel hedge contracts that expired. In addition to the amounts reclassified as a result of expired contracts , in 2015 we recognized a reduction of fuel expense of $1.4 million relating to previously recognized fuel expense as a result of the expiration of the fuel hedge contracts for which the fuel hedging relationship was deemed to be ineffective on a prospective basis in 2014 . As a result, the changes in fair value for those contracts were recorded as expense rather than as a component of other comprehensive loss. At December 31, 2017, all fuel hedge contracts were determined to be highly effective. Based on the amounts in accumulated other comprehens ive income as of December 31, 2017 and the expected timing of the purchases of the diesel hedged, we expect to reclassify approximately $0.6 million, net of tax, on derivative instruments from accumulated other comprehensive income into our results of operations during the next year due to the actual diesel fuel purchases. The amounts actually realized will be dependent on the fair values as of the date of settlement. We perform both a prospective and retrospective assessment of the effectiveness of our hedge contracts at inception and qu arterly, including assessing the possibility of counterparty default. If we determine that a derivative is no longer expected to be highly effective, we discontinue hedge accounting prospectively and recognize subsequent changes in the fair value of the hedge in earnings. As a result of our effectiveness assessment at inception, quarterly, and at December 31, 2017 and 2016, we believe our hedge contracts have been and will continue to be highly effective in offsetting changes in cash flows attributable to the hedged risk. Outstanding financial derivative instruments expose us to credit loss in the event of nonperformance by the counterparties to the agreements. We do not expect any of the counterparties to fail to meet their obligations. Our credit exposure related to these financial instruments is represented by the fair value of contracts reported as assets. To manage credit risk, we review each counterparty's audited financial statements, credit ratings, and/or obtain references as we deem necessary.

13.

DERIVATIVE INSTRUMENTS

We engage in activities that expose us to market risks, including the effects of changes in fuel prices and in interest rates. Financial exposures are evaluate

d as an integral part of our risk management program, which seeks, from time-to-time, to reduce the potentially adverse effects that the volatility of fuel markets and interest rate risk

may

have on operating results.

In an effort to seek to reduce the

variability of the ultimate cash flows associated with fluctuations in diesel fuel prices, we periodically enter into various derivative instruments, including forward futures swap contracts. Specifically, we enter into hedging contracts with respect to ultra-low sulfur diesel (

"ULSD

"). Under these contracts, we pay a fixed rate per gallon of ULSD and receive the monthly average price of Gulf Coast ULSD. The retrospective and prospective regression analyses provided that changes in the prices of diesel fuel and ULSD were deemed to be highly effective based on the relevant authoritative guidance except for a small portion of our hedging contracts, which we determined to be ineffective on a prospective basis in

2015.

Consequently, we recognized a reduction in fuel expense of

$1.4

million in

2015

to mark the related liability to market. At

December 31, 2017

and

2016,

there were

remaining ineffective fuel hedge contracts and, thus, all remaining fuel hedge contracts continue to qualify as cash flow hedges. We do

not

engage in speculative transactions, nor do we hold or issue financial instruments for trading purposes

Effective

December 31, 2017,

we adopted

ASU

2017

12,

which eliminates the requirement to separately measure and report hedge ineffectiveness. For the years ended

2017,

2016,

and

2015,

hedge ineffectiveness has been recorded, thus

adjustments were required

August 2015,

we entered into an interest rate swap agreement with a notional amount of

$28.0

million, which was designated as

a hedge against the variability in future interest payments due on the debt associated with the purchase of our corporate headquarters. The terms of the swap agreement effectively convert the variable rate interest payments on this note to a fixed rate of

4.2%

through maturity on

August 1, 2035

. In

2016,

we also entered into several interest rate swaps, which were designated to hedge against the variability in future interest rate payments due on rent associated with the purchase of certain trailers. Because the critical terms of the swap and hedged item coincide, in accordance with the requirements of ASC

815,

the change in the fair value of the derivative is expected to exactly offset changes in the expected cash flows due to fluctuations in the LIBOR rate over the term of the debt instrument, and therefore

ongoing assessment of effectiveness is required. The fair value of the swap agreements that were in effect at

December 31, 2017

and

2016,

of approximately

$0.4

million and

$0.7

million, respectively, is included in other assets and other liabilities, as appropriate, in the consolidated balance sheet, and is included in accumulated other comprehensive income (loss), net of tax. Additionally,

$0.4

million and

$0.6

million was reclassified from accumulated other comprehensive income (loss) into our results of operations as additional interest expense for the year ended

December 31, 2017

and

2016,

respectively, related to changes in interest rates during such periods. Based on the amounts in accumulated other comprehensive income (loss) as of

December 31, 2017,

we expect to reclassify losses of approximately

$0.2

million, net of tax, on derivative instruments from accumulated other comprehensive income (loss) into our results of operations during the next

twelve

months due to changes in interest rates. The amounts actually realized will depend on the fair values as of the date of settlement.

We recognize all derivative instruments at fair value on our consolidated balance sheets. Our derivati

ve instruments are designated as cash flow hedges, thus the gain or loss on the derivatives is reported as a component of accumulated other comprehensive income (loss) and will be reclassified into earnings in the same period during which the hedged transaction affects earnings. The change in fair value of the hedge offsets the change in fair value of the hedged item

December 31, 2017

, we had fuel hedge contracts on approximately

7.6

million gallons of diesel to be purchased in

2018,

or approximately

16.1%

of our projected annual

2018

fuel requirements.

The fair value of the contracts that were in effect at

December 31,

2017

and

2016,

of approximately

$0.8

million and

$3.6

million, respectively, are included in other assets and other liabilities, respectively, in the consolidated balance sheet, and are included in accumulated other comprehensive income (loss), net of tax

Changes in the fair values of these instruments can vary dramatically based on changes in the underlying commodity prices. For example, during

2017,

market "spot" prices for ULSD peaked at a high of approximately

$1.97

per gallon and hit a low price of approximately

$1.33

per gallon. During

2016,

market spot prices ranged from a high of

$1.66

per gallon to a low of

$0.83

per gallon. Market price changes can be driven by factors such as supply and demand, inventory levels, weather events, refinery capacity, political agendas, the value of the U.S. dollar, geopolitical events, and general economic conditions, among other items.

Additionally,

$4.1

million,

$16.7

million, and

$15.3

million were reclassified from accumulated other comprehensive income (loss) into our results of operations for the years ended

December 31, 2017,

2016,

and

2015,

respectively, as additional fuel expense for

2017,

2016,

and

2015,

related to losses on fuel hedge contracts that expired. In addition to the amounts reclassified as a result of expired contracts

, in

2015

we recognized a reduction of fuel expense of

$1.4

million relating to previously recognized fuel expense as a result of the expiration of the fuel hedge contracts for which the fuel hedging relationship was deemed to be ineffective on a prospective basis in

2014

. As a result, the changes in fair value for those contracts were recorded as expense rather than as a component of other comprehensive loss. At

December 31, 2017,

all fuel hedge contracts were determined to be highly effective.

Based on the amounts in accumulated other comprehens

ive income as of

December 31, 2017

and the expected timing of the purchases of the diesel hedged, we expect to reclassify approximately

$0.6

million, net of tax, on derivative instruments from accumulated other comprehensive income into our results of operations during the next year due to the actual diesel fuel purchases. The amounts actually realized will be dependent on the fair values as of the date of settlement.

We perform both a prospective and retrospective assessment of the effectiveness of our hedge contracts at inception and qu

arterly, including assessing the possibility of counterparty default. If we determine that a derivative is

longer expected to be highly effective, we discontinue hedge accounting prospectively and recognize subsequent changes in the fair value of the hedge in earnings. As a result of our effectiveness assessment at inception, quarterly, and at

December 31, 2017

and

2016,

we believe our hedge contracts have been and will continue to be highly effective in offsetting changes in cash flows attributable to the hedged risk.

Outstanding financial derivative instruments expose us to credit loss in the event of nonperformance by the counterparties to the agreements. We do

not

expect any of the counterparties to fail to meet their obligations.

Our credit exposure related to these financial instruments is represented by the fair value of contracts reported as assets. To manage credit risk, we review each counterparty's audited financial statements, credit ratings, and/or obtain references as we deem necessary.