Common Stock [Member] 6.50% Convertible Notes due 2029 [Member] 6.00% Notes due 2026 [Member] 4.75% Convertible Senior Notes due 2023 [Member] 5.25% Convertible Senior Notes due 2018 [Member] Credit Facility [Member] Preferred Stock [Member] Subscription Rights [Member] Warrants [Member] Common Stock [Member] 6.00% Notes due 2026 [Member] 5.25% Convertible Senior Notes due 2018 [Member] 6.50% Convertible Notes due 2029 [Member] 4.75% Convertible Senior Notes due 2023 [Member] Credit Facility [Member] Preferred Stock [Member] Subscription Rights [Member] Warrants [Member]