Stockholders Equity and Stock Options (Narrative) (Details) (USD $)	7 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2011 Y	Dec. 31, 2010	Dec. 31, 2009	Jan. 03, 2012
Treasury Stock, Shares	244,113	244,113	243,040
Preferred Stock, Shares Authorized	20,000,000	20,000,000
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Outstanding	0	0	0
Additional shares available for issuance under the plan					552,466
Annual percentage increase in number of shares available for issuance		1.50%
Number of shares authorized	3,093,371	3,093,371
Number of shares available for grant	4,399,273	4,399,273
Plan expiration date		May 2021
Allocated Share-based Compensation Expense		$ 9,200,000	$ 7,400,000	$ 8,300,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures		986,000	944,500	1,359,500
Stock-based compensation expense capitalized		0	0	0
Tax benefits from the exercise of stock options, vested cancellations and the vesting of restricted stock		(236,000)	(365,000)	1,097,000
Contractual Life Of Option Grants		5 years	5 years	5 years
Maximum contractual term, years		8
Share Based Compensation Arrangement By Share Based Payment Award Vesting Rate	33.30%	33.30%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years	3 years	3 years
Expected dividend yield on option grant	2.00%	0.70%	0.00%	0.00%
Expected semi-annual cash dividend	$ 0.42	$ 0.42
Weighted-average exercise price per share, date of grant	$ 38.56	$ 38.56	$ 46.50	$ 47.65
Weighted-average fair value of options granted		$ 9.14	$ 12.87	$ 13.58
Combined fair value of options granted and vested		7,800,000	7,700,000	6,900,000
Unrecognized compensation expense related to outstanding stock options expected to vest	$ 10,700,000	$ 10,700,000
Expected weighted-average period to recognize expense, years		1.8
Stock Options [Member]
Typical Stock Option Vesting Number Of Equal Installment		3
Restricted Stock Granted to Employees [Member]
Increments On First Second And Third Anniversaries Of Grant Date Restricted Shares Issued To Employees		33.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period		3 years
Restricted Stock Granted to Board of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period		1 year
Common Class A [Member]
Common Stock, Shares Authorized	150,000,000	150,000,000	150,000,000
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01	$ 0.01
Common Stock, Shares, Outstanding	23,638,218	23,638,218	23,153,509
Common Stock, Voting Rights, Number of Vote Entitled Per Share		1
Additional shares available for issuance under the plan	1,500,000	1,500,000
Common Class B [Member]
Common Stock, Shares Authorized	50,000,000	50,000,000	50,000,000
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01	$ 0.01
Common Stock, Shares, Outstanding	13,192,845	13,192,845	13,275,345
Common Stock, Voting Rights, Number of Vote Entitled Per Share		10
Common Stock, Conversion to Class A, Ratio		1
Common Class B [Member] | Going Private Transaction [Member]
Common Stock, Voting Rights, Number of Vote Entitled Per Share		1