Share-Based Compensation And Capital Stock Narrative (Details) (USD $)	12 Months Ended			1 Months Ended	12 Months Ended																				0 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Feb. 28, 2013 Scenario, Forecast [Member]	Dec. 31, 2012 Stock Options	Dec. 31, 2011 Stock Options	Dec. 31, 2010 Stock Options	Dec. 31, 2012 Performance Vested Restricted Stock Units [Member]	Dec. 31, 2011 Performance Vested Restricted Stock Units [Member]	Dec. 31, 2010 Performance Vested Restricted Stock Units [Member]	Dec. 31, 2012 Performance Vested Restricted Stock Units [Member] Minimum	Dec. 31, 2012 Performance Vested Restricted Stock Units [Member] Maximum	Dec. 31, 2010 Performance Vested Restricted Stock Units [Member] Target Performance Not Met [Member]	Dec. 31, 2011 Performance Vested Restricted Stock Units [Member] Target Performance Not Met Additional [Member]	Dec. 31, 2010 Performance Vested Restricted Stock Units [Member] Target Performance Not Met Additional [Member]	Dec. 31, 2012 Performance Vested Restricted Stock Units [Member] Scenario, Adjustment [Member]	Dec. 31, 2011 Performance Vested Restricted Stock Units [Member] Scenario, Adjustment [Member]	Dec. 31, 2010 Performance Vested Restricted Stock Units [Member] Scenario, Adjustment [Member]	Dec. 31, 2012 Stock Repurchase Program [Member]	Dec. 31, 2011 Stock Repurchase Program [Member]	Dec. 31, 2012 Stock Repurchase Program Aggregate Total [Member]	Dec. 31, 2012 Stock Repurchase Program Aggregate Total [Member] Prior To Stock Split [Member]	Dec. 31, 2012 Minimum Tax Withholding Requirements [Member] [Member]	Dec. 31, 2011 Minimum Tax Withholding Requirements [Member] [Member]	Jul. 27, 2012 2012 Special Cash Dividend [Member]	Aug. 23, 2012 2012 Special Cash Dividend [Member]
Cash dividends declared per share	$ 0.74	$ 0.74		$ 0.185
Dividends, Common Stock, Cash	$ 42,700,000	$ 43,500,000
Common Stock, Special Dividends, Per Share, Declared																									$ 10.41
Payments of Special Dividends																										600,700,000
Number of Shares Authorized	4,600,000
Number of Shares Available for Grant	900,000
Options granted					160,408	166,306	261,137
Options granted, fair value					1,600,000	2,100,000	2,600,000
Aggregate intrinsic value of stock, options, outstanding					15,500,000
Aggregate intrinsic value of the stock options, exercisable						10,700,000
Total intrinsic value of options exercised					2,800,000	2,800,000	2,000,000
Proceeds from exercise of stock options	7,090,000	3,845,000	2,457,000		7,100,000	3,800,000	2,500,000
Stock options exercised					266,754	175,386	123,109
Stock Option Adjustment due to Special Dividend					497,497			0
Percentage Adjustment to Stock Option Exercise Price due to Special Dividend					24.00%
Vesting Range											0.00%	200.00%
Vesting Percentage For Stock based Award Target Achievement											100.00%	160.00%
Stock units forfeited								57,176	43,179	13,110			4,661	39,070	4,989
Grants vested								0	0	10,880
Grant date fair value of shares vested										400,000
Grant, initial target										15,541
Stock Award Performance Percentage Target Achieved										70.00%
Remaining Stock Awards Forfeited Upon Employee Termination									4,109						3,460
Allocated Share-based Compensation Expense	11,300,000	11,200,000	8,900,000		2,100,000	2,800,000	2,400,000	1,700,000	700,000	(300,000)						500,000	100,000	(800,000)
Stock Repurchased During Period, Shares																			500,000	1,600,000	45,300,000	33,000,000
Common stock purchased under stock repurchase program, value	22,947,000	53,414,000	11,165,000																19,900,000	51,000,000	1,100,000,000
Common stock redeemed, shares																							75,105	67,426
Common stock redeemed, value																							$ 2,700,000	$ 2,600,000