Credit Facilities (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Debt and Credit Arrangements [Abstract]
Line of Credit Facility, Expiration Date	Dec. 12, 2018
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,000.0
Line of Credit Facility, Increase (Decrease), Net	250.0
Line of Credit Facility, Amount Outstanding	$ 200.0
Line of Credit Facility, Covenant Compliance	June 30, 2014