Share-Based Compensation and Capital Stock - Summary of Change in Stock-Based Award Activity (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at January 1 - Shares	1,661,952		1,934,034		1,573,726
Granted - Shares	651,757		173,413		160,408
Special Dividend Adjustment - Shares					497,497
Exercised - Shares	(390,290)		(347,180)		(266,754)
Expired - Shares	0		(75,473)
Forfeited - Shares	(20,242)		(22,842)		(30,843)
Outstanding at December 31 - Shares	1,903,177		1,661,952		1,934,034
Options Exercisable at December 31 - Shares	995,173		1,181,374		1,302,624
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding at January 1 - Weighted average exercise price (in dollars per share)	$ 26.44		$ 25.80	[1]	$ 33.30	[1]
Granted - Weighted average exercise price (in dollars per share)	$ 45.59		$ 36.76		$ 35.60	[1]
Special Dividend Adjustment - Weighted average exercise price (in dollars per share)					$ 25.31	[1]
Exercised - Weighted average exercise price (in dollars per share)	$ 25.87		$ 25.54		$ 26.57	[1]
Expired - Weighted average exercise price (in dollars per share)	$ 0.00		$ 36.99
Forfeited - Weighted average exercise price (in dollars per share)	$ 34.33		$ 28.94		$ 36.67	[1]
Outstanding at December 31 - Weighted average exercise price (in dollars per share)	$ 33.03		$ 26.44		$ 25.80	[1]
Options Exercisable at December 31 - Weighted average exercise price (in dollars per share)	$ 25.06		$ 24.61		$ 25.62	[1]
Weighted Average Remaining Contractual Life - Outstanding at December 31	3 years 9 months 18 days		3 years		4 years
Weighted Average Remaining Contractual Life - Options Exercisable at December 31	2 years		2 years 2 months 12 days		3 years 1 month 6 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at January 1 - Shares	563,345		606,547		565,627
Granted - Shares	154,833		225,240		266,159
Vested - Shares	(214,818)		(227,890)		(198,415)
Forfeited - Shares	(23,804)		(40,552)		(26,824)
Outstanding at December 31 - Shares	479,556		563,345		606,547
Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding at January 1 - Weighted average grant date fair value (in dollars per share)	$ 36.64		$ 35.17		$ 34.43
Weighted average grant date fair value (in dollars per share)	$ 46.81		$ 37.74		$ 35.76
Vested - Weighted average grant date fair value (in dollars per share)	$ 35.91		$ 33.94		$ 33.75
Forfeited - Weighted average grant date fair value (in dollars per share)	$ 38.97		$ 35.85		$ 36.06
Outstanding at December 31 - Weighted average grant date fair value (in dollars per share)	$ 40.14		$ 36.64		$ 35.17
Performance Vested Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at January 1 - Shares	216,342		170,116		109,769
Granted - Shares	24,678		80,184		117,523
Performance-Based Leveraging - Shares	10,251	[2]	9,192	[3]
Vested - Shares	(28,886)		(39,816)		0
Forfeited - Shares	(22,099)		(3,334)		(57,176)
Outstanding at December 31 - Shares	200,286		216,342		170,116
Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding at January 1 - Weighted average grant date fair value (in dollars per share)	$ 37.34		$ 35.56		$ 35.57
Weighted average grant date fair value (in dollars per share)	$ 45.59		$ 39.48		$ 35.27
Performance-Based Leveraging - Weighted average grant date fair value (in dollars per share)	$ 41.25		$ 32.60
Vested - Weighted average grant date fair value (in dollars per share)	$ 41.25		$ 32.60		$ 0.00
Forfeited - Weighted average grant date fair value (in dollars per share)	$ 34.77		$ 41.25		$ 34.98
Outstanding at December 31 - Weighted average grant date fair value (in dollars per share)	$ 38.28		$ 37.34		$ 35.56

[1] The weighted average exercise price for options outstanding and exercisable reflect the reduction of the option price for outstanding options as described under "Special Dividend Adjustment". The weighted average exercise price for options granted, exercised or forfeited reflects the option price in effect at the time of the transaction.

[2] PVRSU units outstanding have been increased by 10,251 units during the year ended December 31, 2014, due to the Company exceeding the targeted performance conditions contained in PVRSU's granted in prior periods

[3] PVRSU units outstanding have been increased by 9,192 units during the year ended December 31, 2013, due to the Company exceeding the targeted performance conditions contained in PVRSU's granted in prior periods.