Note 14 - Senior Notes Payable - Senior Notes Payable (Details) (Parentheticals)	Sep. 30, 2017	Aug. 31, 2017	Jun. 30, 2017	Apr. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Mar. 31, 2016
8.4% Senior Notes Due May 2017 [Member]
Interest rate				8.40%
1.625% Convertible Senior Notes due May 2018 [Member]
Interest rate	1.625%					1.625%	1.625%
0.25% Convertible Senior Notes Due June 2019 [Member]
Interest rate	0.25%					0.25%
5.875% Senior Notes Due November 2024 [Member]
Interest rate				5.875%
5.25% Senior Notes due June 2026 [Member]
Interest rate				5.25%
5.00% Senior Notes Due 2027 [Member]
Interest rate			5.00%
1.25% Convertible Senior Notes Due August 2032 [Member]
Interest rate	1.25%	1.25%				1.25%
Homebuilding [Member] | 8.4% Senior Notes Due May 2017 [Member]
Interest rate					8.40%
Homebuilding [Member] | 8.375% Senior Notes Due May 2018 [Member]
Interest rate	8.375%				8.375%
Homebuilding [Member] | 1.625% Convertible Senior Notes due May 2018 [Member]
Interest rate	1.625%				1.625%
Homebuilding [Member] | 0.25% Convertible Senior Notes Due June 2019 [Member]
Interest rate	0.25%				0.25%
Homebuilding [Member] | 6.625% Senior Notes due May 2020 [Member]
Interest rate	6.625%				6.625%
Homebuilding [Member] | 8.375% Senior Notes Due January 2021 [Member]
Interest rate	8.375%				8.375%
Homebuilding [Member] | 6.25% Senior Notes Due December 15, 2021 [Member]
Interest rate	6.25%				6.25%
Homebuilding [Member] | 5.375% Senior Notes Due October 2022 [Member]
Interest rate	5.375%				5.375%
Homebuilding [Member] | 5.875% Senior Notes Due November 2024 [Member]
Interest rate	5.875%				5.875%
Homebuilding [Member] | 5.25% Senior Notes due June 2026 [Member]
Interest rate	5.25%				5.25%
Homebuilding [Member] | 5.00% Senior Notes Due 2027 [Member]
Interest rate	5.00%
Homebuilding [Member] | 1.25% Convertible Senior Notes Due August 2032 [Member]
Interest rate	1.25%				1.25%