Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
NET INCOME	$ (2,470.3)	$ 293.8	$ 262.7	$ 327.9	$ (3,448.5)	$ 432.9	$ (1,169.6)	$ 296.7	$ (1,585.9)	$ (3,888.5)	$ 1,427.9
OTHER COMPREHENSIVE INCOME (LOSS), NET
Net change in fair value of derivatives									(23.6)	(11.7)	(5.8)
Reclassification of gains and losses on derivative instruments from other comprehensive (income) loss into net income									22.2	(0.9)	2.0
Other									2.0	6.3	1.9
NET OTHER COMPREHENSIVE INCOME (LOSS)									0.6	(6.3)	(1.9)
COMPREHENSIVE INCOME									(1,585.3)	(3,894.8)	1,426.0
COMPREHENSIVE INCOME ATTRIBUTABLE TO NONCONTROLLING INTERESTS									(8.9)	(14.1)	(9.7)
COMPREHENSIVE INCOME ATTRIBUTABLE TO ENSCO									$ (1,594.2)	$ (3,908.9)	$ 1,416.3