Financial Instruments (Narrative) (Details) (USD $) In Millions, unless otherwise specified		3 Months Ended	0 Months Ended	3 Months Ended		3 Months Ended
	Mar. 31, 2014	Mar. 31, 2014 Private Placement, Notes [Member]	Mar. 24, 2014 Credit Agreement [Member]	Mar. 31, 2014 Credit Agreement [Member]	Jan. 16, 2014 Credit Agreement [Member]	Mar. 31, 2014 Credit Agreement [Member] Minimum [Member]	Mar. 31, 2014 Credit Agreement [Member] Maximum [Member]	May 20, 2013 Credit Agreement [Member] Interest Rate Swap [Member]	Jul. 16, 2010 Credit Agreement [Member] Interest Rate Swap [Member]
Debt Instrument [Line Items]
Debt issued		$ 150
Interest rate		6.84%
Maturity date		Oct. 25, 2017
Year of maturity				2018
Payment required on October 25, 2015		50
Fair value of long-term debt		114.6
Amount of credit facility				330
Amount of credit facility outstanding				199
Additional amount that can be borrowed on facility				131
Notional amount								$ 110	$ 105
Fixed interest rate in swap								1.414%	2.04%
LIBOR spread			1.375%			1.25%	1.875%
Effective annual rate				3.415%
Maximum leverage ratio allowed	3.50
Minimum interest coverage ratio required	3.00
Leverage ratio	1.75
Interest coverage ratio	9.68
LIBOR rate				0.152%	0.24%