Note 5 - Long-Term Debt and Credit Facility (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended															9 Months Ended		9 Months Ended
	Sep. 30, 2013	Jul. 02, 2013	Dec. 31, 2012	Sep. 30, 2013 Wasco Energy [Member]	Dec. 31, 2012 Wasco Energy [Member]	Sep. 30, 2013 Bayou Wasco [Member]	Sep. 30, 2013 Initial [Member]	Dec. 31, 2012 Initial [Member]	Sep. 30, 2013 Additional [Member]	Dec. 31, 2012 Additional [Member]	Sep. 30, 2013 Insurance Carriers Collateral [Member]	Sep. 30, 2013 Work Performance Obligations [Member]	Dec. 31, 2012 Bayou Wasco [Member]	Sep. 30, 2013 BPPC [Member]	Dec. 31, 2012 BPPC [Member]	Sep. 30, 2013 2013 Credit Facility [Member]	Jul. 02, 2013 2013 Credit Facility [Member]	Sep. 30, 2013 2013 Credit Facility [Member] Minimum [Member]	Sep. 30, 2013 2013 Credit Facility [Member] Maximum [Member]	Dec. 31, 2012 2011 Credit Facility [Member]	Aug. 31, 2011 2011 Credit Facility [Member]
Note 5 - Long-Term Debt and Credit Facility [Line Items]
Debt Instrument, Face Amount																	$ 650.0			$ 250.0	$ 500.0
Line of Credit Facility, Maximum Borrowing Capacity																	300.0
Line of Credit Facility, Term		5 years
Secured Debt																345.6	350.0
Term Loan, Term		5 years
Debt Instrument, Maturity Date	Jul. 01, 2018
Debt Instrument, Basis Spread on Variable Rate																		1.25%	2.25%
Debt Instrument, Description of Variable Rate Basis																one month LIBOR borrowing rate
Debt Instrument, Interest Rate at Period End																2.21%
Unsecured Debt			218.8
Line of Credit Facility, Amount Outstanding		35.5														35.5				26.0
Significant Acquisitions and Disposals, Acquisition Costs or Sale Proceeds		147.6
Credit Facility, Retired Amount		232.3
Business Combination, Consideration Paid		7.0
Other Loans Payable	0.3		0.1
Due from Joint Ventures			4.1	6.9	5.5	14.0	8.0	8.0	6.2	6.2			11.0	14.2	14.2
Other Long-term Debt	5.0		5.2
Letters of Credit Outstanding, Amount	18.7										10.4	8.3
Long-term Debt, Fair Value	385.8		253.6
Derivative, Amount of Hedged Item	175.0
Derivative, Fixed Interest Rate Percentage	0.87%
Credit Facility Maximum Consolidated Leverage Ratio	3.75
CreditFacilityMinimumConsolidatedLeverageRatio	3.5
Credit Facility Actual Consolidated Leverage Ratio	2.64
Line of Credit Facility, Remaining Borrowing Capacity	$ 163.6
Credit Facility Minimum Consolidated Fixed Charge Ratio	1.25
Credit Facility Actual Consolidated Fixed Charge Ratio	1.85