Stockholders' Equity (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 IncentivePlan	Dec. 31, 2012	Dec. 31, 2011	Aug. 06, 2013
Stock Award and Incentive Plan [Abstract]
Number of incentive plans	2
Voting Rights [Abstract]
Term of nonqualified stock options, maximum (in years)	10 years
Percentage options granted under plans vest after three years (in hundredths)	75.00%
Percentage options granted under plan vest after four years (in hundredths)	100.00%
Vesting period for 75 percent of stock options	3 years
Vesting period for 100 percent of stock options	4 years
Weighted Average Exercise Price [Roll Forward]
Restricted stock award shares approved grant date fair value (in dollars per share)				$ 57.86
Percentage stock based compensation expense recognize over three years vesting period (in hundredths)	30.00%
Percentage stock based compensation expense recognize over five years vesting period (in hundredths)	70.00%
Vesting period for recognition of 30 percent of stock based compensation expense (in years)	3 years
Vesting period for recognition of 70 percent of stock based compensation expense (in years)	5 years
Stock based compensation expense	$ 2,100,000	$ 13,600,000	$ 2,600,000
Actual and projected stock based compensation expense for RSA shares and options [Abstract]
Actual stock based compensation expense	2,072,000	13,583,000	2,588,000
Projected stock based compensation expense 2014	6,748,000
Projected stock based compensation expense 2015	6,733,000
Projected stock based compensation expense 2016	5,763,000
Projected stock based compensation expense 2017	3,382,000
Projected stock based compensation expense 2018	2,791,000
Projected stock based compensation expense 2019	1,158,000
Projected stock based compensation expense 2020	840,000
Projected stock based compensation expense 2021	567,000
Projected stock based compensation expense 2022	328,000
Projected stock based compensation expense 2023	117,000
Compensation cost related to non-vested restricted stock awards and options not yet recognized	28,400,000
Proceeds from exercise of stock options	76,000	920,000	0
Tax benefit from exercise of stock options	16,000	105,300
Tax benefit from RSA compensation	800,000	5,000,000	843,000
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price [Line Items]
Options currently exercisable (in shares)	62,000	59,623
Exercise price of options currently exercisable (in dollars per share)	$ 42.14	$ 41.12
Weighted average fair value of options granted	$ 18.66
Assumptions made [Abstract]
Expected volatility (in hundredths)	49.00%
Risk free interest rate (in hundredths)	0.15%
Expected life	5 years
Dividend yield (in hundredths)	0.26%
Expected volatility term		4 years
Estimated Quarterly dividend factored into the fair value of options (in dollars per share)	$ 0.03
The weighted average remaining contractual life of the outstanding options	2 years 8 months 8 days
$39.55 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price [Line Items]
Exercise price (in dollars per share)	$ 39.55
Options outstanding (in shares)	10,000
Weighted average remaining contractual life	2 years 3 months 29 days
Options currently exercisable (in shares)	10,000
Exercise price of options currently exercisable (in dollars per share)	$ 39.55
$39.65 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price [Line Items]
Exercise price (in dollars per share)	$ 39.65
Options outstanding (in shares)	20,000
Weighted average remaining contractual life	0 years 5 months 1 day
Options currently exercisable (in shares)	20,000
Exercise price of options currently exercisable (in dollars per share)	$ 39.65
$39.90 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price [Line Items]
Exercise price (in dollars per share)	$ 39.90
Options outstanding (in shares)	10,000
Weighted average remaining contractual life	3 years 0 months 29 days
Options currently exercisable (in shares)	10,000
Exercise price of options currently exercisable (in dollars per share)	$ 39.90
$44.90 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price [Line Items]
Exercise price (in dollars per share)	$ 44.90
Options outstanding (in shares)	10,000
Weighted average remaining contractual life	1 year 9 months 29 days
Options currently exercisable (in shares)	10,000
Exercise price of options currently exercisable (in dollars per share)	$ 44.90
$45.77 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price [Line Items]
Exercise price (in dollars per share)	$ 45.77
Options outstanding (in shares)	10,000
Weighted average remaining contractual life	7 years 0 months 29 days
Options currently exercisable (in shares)	0
$51.74 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price [Line Items]
Exercise price (in dollars per share)	$ 51.74
Options outstanding (in shares)	6,000
Weighted average remaining contractual life	4 years 3 months 29 days
Options currently exercisable (in shares)	6,000
Exercise price of options currently exercisable (in dollars per share)	$ 51.74
Class A [Member]
Voting Rights [Abstract]
Number of votes per share	1
Number of shares reserved for issuance under each plan, maximum (in shares)	1,500,000
Class B [Member]
Voting Rights [Abstract]
Number of votes per share	10
Stock Options [Member]
Shares outstanding [Roll Forward]
Outstanding at beginning of period (in shares)	68,623	100,900
Granted (in shares)	0	0	10,000
Forfeited (in shares)	0	(500)
Exercised / Vested (in shares)	(2,623)	(31,777)
Outstanding at end of period (in shares)	66,000	68,623	100,900
Shares available for future issuance at the end of the period	1,973,725
Weighted Average Exercise Price [Roll Forward]
Outstanding at beginning of period (in dollars per share)	$ 41.79	$ 37.81
Granted (in dollars per share)	$ 0	$ 0
Forfeited (in dollars per share)	$ 0	$ 28.95
Exercised / Vested (in dollars per share)	$ 28.95	$ 28.95
Outstanding at end of period (in dollars per share)	$ 42.49	$ 41.79	$ 37.81
Weighted average exercise price of the exercisable outstanding stock options (in dollars per share)			$ 45.77
Actual and projected stock based compensation expense for RSA shares and options [Abstract]
Stock options exercised (in shares)	(2,623)	(31,777)
Restricted Stock [Member]
Shares outstanding [Roll Forward]
Outstanding at beginning of period (in shares)	0	275,600
Granted (in shares)	576,950	105,300	197,200
Forfeited (in shares)	(10,000)	(7,900)
Exercised / Vested (in shares)	0	(373,000)
Outstanding at end of period (in shares)	566,950	0	275,600
Weighted Average Exercise Price [Roll Forward]
Outstanding at beginning of period (in dollars per share)	$ 0	$ 45.56
Granted (in dollars per share)	$ 63.82	$ 43.49
Forfeited (in dollars per share)	$ 57.86	$ 45.21
Exercised / Vested (in dollars per share)	$ 0	$ 44.99
Outstanding at end of period (in dollars per share)	$ 63.93	$ 0	$ 45.56
Restricted stock award shares approved grant date fair value (in dollars per share)	$ 63.82	$ 43.49	$ 48.80
RSA shares outstanding (in shares)	566,950
Average weighted grant price (in dollars per share)	$ 63.93
Stock based compensation expense		$ 10,100,000
Actual and projected stock based compensation expense for RSA shares and options [Abstract]
Stock options exercised (in shares)	0	(373,000)
Restricted stock awards - August 2013 [Member]
Weighted Average Exercise Price [Roll Forward]
Percentage stock based compensation expense recognize over three years vesting period (in hundredths)	30.00%
Percentage stock based compensation expense recognize over five years vesting period (in hundredths)	10.00%
Vesting period for recognition of 30 percent of stock based compensation expense (in years)	3 years
Maximum [Member] | Restricted stock awards - August 2013 [Member]
Weighted Average Exercise Price [Roll Forward]
Vesting period for recognition of 70 percent of stock based compensation expense (in years)	10 years
Minimum [Member] | Restricted stock awards - August 2013 [Member]
Weighted Average Exercise Price [Roll Forward]
Vesting period for recognition of 70 percent of stock based compensation expense (in years)	4 years