Derivative Instruments (Gains And Losses On Derivatives Designated As Cash Flow Hedges) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Interest Rate Lock Contracts [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income ("OCI") (Effective Portion)	[1]	$ 0.0	$ 0.0
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income ("AOCI") into Income (Effective Portion)	[1],[2]	(0.1)	(0.1)
Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	[1],[3]	0.0	0.0
Foreign Currency Forward Contracts [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income ("OCI") (Effective Portion)	[4]	3.5	(17.4)
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income ("AOCI") into Income (Effective Portion)	[2],[4]	(5.8)	(4.9)
Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	[3],[4]	1.1	(0.1)
Foreign Currency Forward Contracts [Member] | Contract Drilling [Member]
Derivative [Line Items]
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income ("AOCI") into Income (Effective Portion)		(6.0)
Foreign Currency Forward Contracts [Member] | Depreciation Expense [Member]
Derivative [Line Items]
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income ("AOCI") into Income (Effective Portion)		0.2	0.2
Cash Flow Hedges [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income ("OCI") (Effective Portion)		3.5	(17.4)
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income ("AOCI") into Income (Effective Portion)	[2]	(5.9)	(5.0)
Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	[3]	1.1	(0.1)
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income ("AOCI") into Income (Effective Portion)			(5.1)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		$ 4.4	$ (13.5)

[1] Losses on interest rate lock derivatives reclassified from AOCI into income (effective portion) were included in interest expense, net, in our condensed consolidated statements of income.

[2] Changes in the fair value of cash flow hedges are recorded in AOCI. Amounts recorded in AOCI associated with cash flow hedges are subsequently reclassified into contract drilling, depreciation or interest expense as earnings are affected by the underlying hedged forecasted transaction.

[3] Gains and losses recognized in income for ineffectiveness and amounts excluded from effectiveness testing were included in other, net, in our condensed consolidated statements of income.

[4] During 2016, $6.0 million of losses were reclassified from AOCI into contract drilling expense and $200,000 of gains were reclassified from AOCI into depreciation expense in our condensed consolidated statement of income. During the prior year quarter, $5.1 million of losses were reclassified from AOCI into contract drilling expense and $200,000 of gains were reclassified from AOCI into depreciation expense in our condensed consolidated statement of income.