Stock-Based Compensation and Equity (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at beginning of year - shares	794,210	1,208,041	1,699,701
Exercised - shares	(169,412)	(410,331)	(449,660)
Forfieted/ Expired - shares	(5,197)	(3,500)	(42,000)
Outstanding at end of year - shares	619,601	794,210	1,208,041
Vested and expected to vest at end of year - shares	619,601
Exercisable at end of year - shares	511,811	623,218	959,779
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding at beginning of year - weighted average excercise price	$ 30.32	$ 28.73	$ 28.57
Exercised - weighted average exercise price	$ 30.43	$ 25.94	$ 27.71
Forfieted/ Expired - weighted average excercise price	$ 29.84	$ 24.93	$ 32.85
Outstanding at end of year - weighted average excercise price	$ 30.30	$ 30.32	$ 28.73
Vested and expected to vest at end of year - weighted average excercise price	$ 30.30
Exercisable at end of year - weighted average exercise price	$ 30.18	$ 30.22	$ 28.36
Outstanding at end of year - weighted average contractual term (in Years)	2 years 7 months 4 days	3 years 2 months 9 days	3 years 3 months 16 days
Vested and expected to vest at end of year - weighted average contractual term (in Years)	2 years 7 months 4 days
Exercisable at end of year - weighted average contractual term (in Years)	2 years 5 months 13 days
Outstanding at end of year - aggregate intrinsic value	$ 19,239,738
Vested and expected to vest at end of year - aggregate intrinsic value	19,239,738
Exercisable at end of year- aggregate intrinsic value	$ 15,950,707