Note 14 - Selected Financial Information of Registrant Selected Financial Information of Registrant (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Total assets	$ 5,736,504	$ 6,842,336
Long-term debt	1,224,892	1,192,299
Total liabilities	3,374,560	4,670,586
Equity component of currently redeemable convertible senior notes	8,546	74,690
Total stockholders' equity	2,353,398	2,097,060
Total liabilities and stockholders' equity	5,736,504	6,842,336
Parent Company
Condensed Financial Statements, Captions [Line Items]
Investments in subsidiaries, at equity in net assets	3,018,264	2,746,915
Total assets	3,869,439	3,741,648
Long-term debt	1,224,892	1,192,299
Total liabilities	1,507,495	1,569,898
Equity component of currently redeemable convertible senior notes	8,546	74,690
Total stockholders' equity	2,353,398	2,097,060
Total liabilities and stockholders' equity	$ 3,869,439	$ 3,741,648