Note 7 - Long-Term Debt and Revolving Line of Credit - Interest Margin and Commitment Fee Payable (Details) | 6 Months Ended |
Jun. 30, 2017 |
Debt Instrument Leverage Ratio Less than 1.00 [Member] | |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | 0.15% |
Debt Instrument Leverage Ratio Greater Than Or Equal To 1 But Less Than 2 [Member] | |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | 0.20% |
Debt Instrument Leverage Ratio Greater Than Or Equal To 2 But Less Than 3 [Member] | |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | 0.25% |
Debt Instrument Leverage Ratio Greater Than Or Equal To 3 But Less Than 3.50 [Member] | |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | 0.30% |
Debt Instrument Leverage Ratio Greater Than Or Equal To 3.50 But Less Than 4 [Member] | |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | 0.35% |
Debt Instrument Leverage Ratio Greater Than Or Equal To 4 But Less Than 4.50 [Member] | |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | 0.40% |
Debt Instrument Leverage Ratio Greater Than Or Equal To 4.50 But Less Than 5 [Member] | |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | 0.45% |
Debt Instrument Leverage Ratio Greater Than Or Equal To 5 [Member] | |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | 0.50% |
London Interbank Offered Rate (LIBOR) [Member] | Debt Instrument Leverage Ratio Less than 1.00 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 1.25% |
London Interbank Offered Rate (LIBOR) [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 1 But Less Than 2 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 1.50% |
London Interbank Offered Rate (LIBOR) [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 2 But Less Than 3 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 1.75% |
London Interbank Offered Rate (LIBOR) [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 3 But Less Than 3.50 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 2.25% |
London Interbank Offered Rate (LIBOR) [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 3.50 But Less Than 4 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 2.50% |
London Interbank Offered Rate (LIBOR) [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 4 But Less Than 4.50 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 3.00% |
London Interbank Offered Rate (LIBOR) [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 4.50 But Less Than 5 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 3.50% |
London Interbank Offered Rate (LIBOR) [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 5 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 4.00% |
Base Rate [Member] | Debt Instrument Leverage Ratio Less than 1.00 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 0.00% |
Base Rate [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 1 But Less Than 2 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 0.00% |
Base Rate [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 2 But Less Than 3 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 0.00% |
Base Rate [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 3 But Less Than 3.50 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 0.00% |
Base Rate [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 3.50 But Less Than 4 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 0.25% |
Base Rate [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 4 But Less Than 4.50 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 0.75% |
Base Rate [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 4.50 But Less Than 5 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 1.25% |
Base Rate [Member] | Debt Instrument Leverage Ratio Greater Than Or Equal To 5 [Member] | |
Debt Instrument, Basis Spread on Variable Rate | 1.75% |