Derivative Instruments (Narrative) (Details) (Foreign Currency Forward Contracts [Member]) In Millions, unless otherwise specified	1 Months Ended		3 Months Ended		6 Months Ended			1 Months Ended
	Dec. 31, 2014 Not Designated as Hedging Instrument [Member] USD ($)	Dec. 31, 2014 Not Designated as Hedging Instrument [Member] MXN	Mar. 31, 2014 Not Designated as Hedging Instrument [Member] USD ($)	Mar. 31, 2014 Not Designated as Hedging Instrument [Member] MXN	Jun. 30, 2013 Not Designated as Hedging Instrument [Member] USD ($)	Jun. 30, 2013 Not Designated as Hedging Instrument [Member] MXN	Dec. 31, 2013 Not Designated as Hedging Instrument [Member] USD ($)	Jan. 31, 2015 Not Designated as Hedging Instrument [Member] Subsequent Event [Member] USD ($)	Jan. 31, 2015 Not Designated as Hedging Instrument [Member] Subsequent Event [Member] MXN	Dec. 31, 2014 Offsetting Derivative Instrument [Member] USD ($)	Dec. 31, 2014 Offsetting Derivative Instrument [Member] MXN	Oct. 31, 2014 Offsetting Derivative Instrument [Member] USD ($)	Oct. 31, 2014 Offsetting Derivative Instrument [Member] MXN	Dec. 31, 2013 Offsetting Derivative Instrument [Member] USD ($)	Dec. 31, 2013 Offsetting Derivative Instrument [Member] MXN	Jan. 31, 2015 Offsetting Derivative Instrument [Member] Subsequent Event [Member] USD ($)	Jan. 31, 2015 Offsetting Derivative Instrument [Member] Subsequent Event [Member] MXN
Derivative [Line Items]
Aggregate notional amount of derivative	$ 300.0	4,364.7	$ 345.0	4,642.5	$ 325.0	4,202.3	$ 0	$ 300.0	4,480.4	$ 291.4	4,238.8	$ 30.0	403.7	$ 324.3	4,202.3	$ 298.8	4,364.7
Derivative maturity date	Jan. 15, 2015	Jan. 15, 2015	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2013		Jan. 15, 2016	Jan. 15, 2016	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2013	Jan. 15, 2015	Jan. 15, 2015
Weighted average exchange rate of derivatives (in Ps per USD)		14.55		13.46		12.93			14.93		14.57		13.46		12.96		14.61