Share-Based Compensation and Capital Stock Summary Of Activity Related To PVRSU Grants (Details) (Performance Vested Restricted Stock Units [Member], USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-Based Compensation and Capital Stock [Line Items]
Performance vested restricted stock units granted at target	0	0	24,678	58,902
Weighted average grant date fair value per share (in dollars per share)			$ 45.59	$ 36.76
Aggregate grant date fair value			$ 1,125	$ 2,165
Stock units forfeited	3,900	0	3,900	0
Requisite service period			36 months
Minimum [Member]
Share-Based Compensation and Capital Stock [Line Items]
Requisite service period				22 months
Maximum [Member]
Share-Based Compensation and Capital Stock [Line Items]
Requisite service period				36 months