Note 20 - Subsequent Events - Additional Information (Details)	Nov. 07, 2016 USD ($) Member Director $ / shares shares	Sep. 30, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares
Subsequent Event [Line Items]
Preferred Stock, No Par Value		$ 0	$ 0
Liability for any obligation | $		$ 2,004,000,000	$ 2,035,000,000
Settlement Agreement [Member]
Subsequent Event [Line Items]
Liability for any obligation | $		$ 0
Subsequent Event [Member] | Series A Preferred Stock [Member]
Subsequent Event [Line Items]
Expected closing purchase agreement period	2016-11
Preferred stock, liquidation preference	$ 100
Common stock price equal or exceeds preferred stock conversion price percentage	125.00%
Preferred stock conversion description	The Company will have the right to convert Series A Preferred Stock into Common Stock at any time after the second anniversary of the initial issuance, if the closing price of the Common Stock has equaled or exceeded 125 percent of the then-effective conversion price for 45 trading days within a period of 60 consecutive trading days, with the last trading day of such 60 day period ending on the trading day immediately preceding the business day on which the Company issues a press release announcing the mandatory conversion. Each holder will have the right to convert any shares of Series A Preferred Stock during a specified period in connection with a fundamental change, in which case the conversion rate will be adjusted under certain circumstances and such holder will also be entitled to a payment in respect of accumulated dividends. In addition, the Company will have the right to require holders to convert any shares of Series A Preferred Stock in connection with certain reorganization events, in which case the conversion rate will be adjusted under certain circumstances and the holders will also be entitled to a payment in respect of accumulated dividends. If any shares of Series A Preferred Stock have not been converted prior to the fifth anniversary of the initial issuance of the Series A Preferred Stock, the Company will be required to redeem such shares at par plus the amount of accrued and unpaid dividends.
Preferred stock conversion percentage of outstanding common stock	19.99%
Expected number of members to nominate on conversion basis | Member	2
Number of additional directors to elect if dividends in arrears | Director	2
Subsequent Event [Member] | Purchase Agreement [Member] | Series A Preferred Stock [Member]
Subsequent Event [Line Items]
Purchase agreement date	Nov. 07, 2016
Preferred stock, number of shares issued | shares	2,000,000
Percentage of cash dividend payable on preferred stock	5.50%
Preferred Stock, No Par Value	$ 0
Preferred stock purchase price per share	$ 100
Gross proceeds from issuance of shares | $	$ 200,000,000
Subsequent Event [Member] | Settlement Agreement [Member]
Subsequent Event [Line Items]
Environmental remediation liability payment, description	The Company has no obligation to make a payment under the Settlement Agreement unless the liabilities associated with the remediation covered by the Settlement Agreement exceed $99 million, in which case the Company will be liable for 50% of the portion above $99 million.
Threshold amount of remediation liabilities to make payment | $	$ 99,000,000
Percentage of portion above environmental remediation threshold amount liable to pay	50.00%
Subsequent Event [Member] | Settlement Agreement [Member] | Series A Preferred Stock [Member]
Subsequent Event [Line Items]
Initial conversion rate of preferred stock to common stock	5.7471
Initial conversion price of preferred stock per share of common stock	$ 17.40