Stockholders' Equity (Narrative) (Details) (USD $)	0 Months Ended		1 Months Ended	12 Months Ended
	Dec. 20, 2012	Dec. 28, 2010	Feb. 28, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2007
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends paid per share	$ 2.00	$ 1.50
Dividends paid	$ 45,000,000	$ 33,000,000
Deferred stock units, per share	$ 2.00	$ 1.50	$ 35.85
Deferred stock units, value	1,400,000	400,000	0.3
Reduction in outstanding options exercise price	$ 2.00	$ 1.50
Stock option modification charges				100,000	200,000	400,000
Additional stock option modification expenses expected to be recorded over the next three years				200,000
Shares available for grant				688,712	1,361,718
Amount of compensation exchanged for deferred stock units				200,000	1,100,000	100,000
Deferred stock units issued			7,959
Stock options expiration period, years after grant date				6 years
Vesting period				5 years
Unvested stock options, unrecognized compensation costs				4,600,000
Restricted stock granted, restriction period				1 year
Weighted average diluted shares outstanding excludes shares of common stock subject to stock options				426,788	1,311,330	1,269,003
Shares authorized to repurchase of Common Stock							1,000,000
Chairman And Chief Executive Officer Jason Lippert [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant				85,000
President Scott Mereness [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant				85,000
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum percentage stock option exercise price must be equal to fair market value				100.00%
Minimum holding period of common stock				6 months
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award exercise period				10 years
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs, weighted-average recognition period				3 years
Deferred Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs, weighted-average recognition period				2 years 3 months 18 days
Unrecognized compensation costs				5,600,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs, weighted-average recognition period				10 months 24 days
Unrecognized compensation costs				800,000
Restricted stock granted, shares				29,841	36,260
Restricted stock granted, value per share				$ 30.50	$ 23.17
Restricted stock granted, value				900,000	800,000
Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs, weighted-average recognition period				1 year 4 months 24 days
Unrecognized compensation costs				1,500,000
Stock awards, performance period				3 years
Stock awards, grant date fair value				$ 2,700,000