CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
3 3/8% Convertible Notes due 2026
Deferred tax related to equity component of convertible notes		$ 286,322
Convertible note hedges
Deferred tax related to equity component of convertible notes		$ 234,987
2 3/8% Convertible Notes due 2024
Deferred tax related to equity component of convertible notes	$ 92,512