Note 9 - Fair Value of Assets and Liabilities - Fair Value Measurements, Recorded (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets:
Embedded customer derivative	$ 59	$ 4
Total assets at fair value	59	4
Liabilities:
Total liabilities recorded at fair value	6,498	3,046
Embedded customer derivative	59	4
Total assets at fair value	59	4
Metal Swaps [Member]
Liabilities:
Derivative liability	59	4
Interest Rate Swap [Member]
Liabilities:
Derivative liability	6,439	3,042
Fair Value, Inputs, Level 1 [Member]
Assets:
Embedded customer derivative
Total assets at fair value
Liabilities:
Total liabilities recorded at fair value
Embedded customer derivative
Total assets at fair value
Fair Value, Inputs, Level 1 [Member] | Metal Swaps [Member]
Liabilities:
Derivative liability
Fair Value, Inputs, Level 1 [Member] | Interest Rate Swap [Member]
Liabilities:
Derivative liability
Fair Value, Inputs, Level 2 [Member]
Assets:
Embedded customer derivative	59	4
Total assets at fair value	59	4
Liabilities:
Total liabilities recorded at fair value	6,498	3,046
Embedded customer derivative	59	4
Total assets at fair value	59	4
Fair Value, Inputs, Level 2 [Member] | Metal Swaps [Member]
Liabilities:
Derivative liability	59	4
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]
Liabilities:
Derivative liability	6,439	3,042
Fair Value, Inputs, Level 3 [Member]
Assets:
Embedded customer derivative
Total assets at fair value
Liabilities:
Total liabilities recorded at fair value
Embedded customer derivative
Total assets at fair value
Fair Value, Inputs, Level 3 [Member] | Metal Swaps [Member]
Liabilities:
Derivative liability
Fair Value, Inputs, Level 3 [Member] | Interest Rate Swap [Member]
Liabilities:
Derivative liability