Note 5 - Long-Term Debt and Credit Facility (Detail) (USD $)																								3 Months Ended
	Jun. 30, 2014	Mar. 31, 2013	Dec. 31, 2012	Nov. 30, 2011	Aug. 31, 2011	Aug. 31, 2011 Term Loan [Member]	Mar. 31, 2013 Agreed to Loan [Member] Initial [Member]	Mar. 31, 2013 Agreed to Loan [Member] Additional [Member]	Dec. 31, 2012 Agreed to Loan [Member] Additional [Member]	Mar. 31, 2013 Agreed to Loan [Member]	Dec. 31, 2012 Agreed to Loan [Member]	Mar. 31, 2013 Insurance Carriers Collateral [Member]	Mar. 31, 2013 Work Performance Obligations [Member]	Dec. 31, 2012 Initial [Member]	Mar. 31, 2013 Additional [Member]	Dec. 31, 2012 Additional [Member]	Aug. 31, 2011 Minimum [Member]	Aug. 31, 2011 Maximum [Member]	Mar. 31, 2013 Bayou Wasco [Member]	Dec. 31, 2012 Bayou Wasco [Member]	Mar. 31, 2013 Term Loan [Member]	Dec. 31, 2012 Term Loan [Member]	Nov. 30, 2011 Term Loan [Member]	Mar. 31, 2013 Net Worth Calculation One [Member]	Mar. 31, 2013 Net Worth Calculation Two [Member]	Mar. 31, 2013 Net Worth Calculation Three [Member]
Debt Instrument, Face Amount					$ 500,000,000	$ 250,000,000															$ 250,000,000	$ 250,000,000	$ 250,000,000
Line of Credit Facility, Maximum Borrowing Capacity					250,000,000
Line of Credit Facility, Term					5 years
Term Loan, Term					5 years
Debt Instrument, Basis Spread on Variable Rate																	1.50%	2.50%
Debt Instrument, Interest Rate at Period End		2.53%
Unsecured Debt		212,500,000	218,800,000
Line of Credit Facility, Amount Outstanding		26,000,000	26,000,000
Other Loans Payable		100,000	100,000
Due from Joint Ventures							8,000,000	6,200,000	6,200,000	14,200,000	14,200,000			8,000,000	4,100,000	4,100,000			5,500,000	6,900,000
Other Long-term Debt		5,100,000	5,200,000
Letters of Credit Outstanding, Amount		18,600,000										9,800,000	8,800,000
Long-term Debt, Fair Value		247,400,000	253,600,000
Notional Amount of Interest Rate Derivatives				83,000,000
Derivative, Amount of Hedged Item				83,000,000
Derivative, Fixed Interest Rate				0.89%
Derivative, Variable Interest Rate		2.20%
Credit Facility Maximum Consolidated Leverage Ratio	2.25	2.75
Credit Facility Actual Consolidated Leverage Ratio		2.09
Line of Credit Facility, Remaining Borrowing Capacity		78,800,000
Credit Facility Minimum Consolidated Fixed Charge Ratio		1.25
Credit Facility Actual Consolidated Fixed Charge Ratio		1.51
Debt Instrument, Covenant Description																								80%	50%	100%
Minimum Net Worth Required for Compliance		529,500,000
Credit Facility Net Worth		$ 690,400,000