Derivative Instruments and Hedging Activities - Summary of Cash Flow Hedges (Details) (Interest Rate Swaps [Member], Derivatives in Cash Flow Hedging Relationships [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Interest Rate Swaps [Member] | Derivatives in Cash Flow Hedging Relationships [Member]
Summary of Cash Flow Hedges [Abstract]
Amount of Gain or (Loss) Recognized in OCI on Derivatives, net of tax (Effective Portion)	$ 1.8	$ 0.6