Long-term Equity-based Compensation Plans Schedule of Nonvested Restricted Stock Units Activity (Details) - $ / shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of Performance-based Restricted Stock Units Granted Measured Using a Market Performance Condition	50.00%
Percentage of Performance-based Restricted Stock Units Granted Measured Using Company-specific Metric	50.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	300,827
Time Vested Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock, Nonvested at Beginning of Year, Number	29,448
Restricted Stock, Nonvested at Beginning of Year, Weighted Average Grant Date Fair Value	$ 33.77
Restricted Stock, Grants in Period	0
Restricted Stock, Weighted Average Grant Date Fair Value	$ 0.00
Restricted Stock, Vested in Period	(1,500)
Restricted Stock, Vested in Period, Weighted Average Grant Date Fair Value	$ 29.95
Restricted Stock, Forfeited in Period	(1,275)
Restricted Stock, Forfeitures, Weighted Average Grant Date Fair Value	$ 35.89
Restricted Stock, Nonvested at End of Period, Number	26,673
Restricted Stock, Nonvested at End of Period, Weighted Average Grant Date Fair Value	$ 33.88
Time Vested Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock, Nonvested at Beginning of Year, Number	85,048
Restricted Stock, Nonvested at Beginning of Year, Weighted Average Grant Date Fair Value	$ 36.84
Restricted Stock, Grants in Period	40,201
Restricted Stock, Weighted Average Grant Date Fair Value	$ 27.71
Restricted Stock, Vested in Period	0
Restricted Stock, Vested in Period, Weighted Average Grant Date Fair Value	$ 0.00
Restricted Stock, Forfeited in Period	(16,150)
Restricted Stock, Forfeitures, Weighted Average Grant Date Fair Value	$ 36.18
Restricted Stock, Nonvested at End of Period, Number	109,099
Restricted Stock, Nonvested at End of Period, Weighted Average Grant Date Fair Value	$ 33.57
Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock, Nonvested at Beginning of Year, Number	51,400
Restricted Stock, Nonvested at Beginning of Year, Weighted Average Grant Date Fair Value	$ 42.12
Restricted Stock, Grants in Period	0
Restricted Stock, Weighted Average Grant Date Fair Value	$ 0.00
Restricted Stock, Vested in Period	0
Restricted Stock, Vested in Period, Weighted Average Grant Date Fair Value	$ 0.00
Restricted Stock, Forfeited in Period	(51,400)
Restricted Stock, Forfeitures, Weighted Average Grant Date Fair Value	$ 42.12
Restricted Stock, Nonvested at End of Period, Number	0
Restricted Stock, Nonvested at End of Period, Weighted Average Grant Date Fair Value	$ 0.00
Performance Period	3 years
Performance Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock, Nonvested at Beginning of Year, Number	128,100
Restricted Stock, Nonvested at Beginning of Year, Weighted Average Grant Date Fair Value	$ 41.85
Restricted Stock, Grants in Period	118,435
Restricted Stock, Weighted Average Grant Date Fair Value	$ 27.74
Restricted Stock, Vested in Period	0
Restricted Stock, Vested in Period, Weighted Average Grant Date Fair Value	$ 0.00
Restricted Stock, Forfeited in Period	(9,550)
Restricted Stock, Forfeitures, Weighted Average Grant Date Fair Value	$ 41.76
Restricted Stock, Nonvested at End of Period, Number	236,985
Restricted Stock, Nonvested at End of Period, Weighted Average Grant Date Fair Value	$ 34.80
Performance Period, 2016 to 2018 [Member] | Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Additional Shares To Be Granted If Maximum Perfornance Level Is Met or Exceeded	118,435
Performance Period, 2015 to 2017 [Member] | Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Additional Shares To Be Granted If Maximum Perfornance Level Is Met or Exceeded	62,925
Performance Period, 2014 to 2016 [Member] | Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Additional Shares To Be Granted If Maximum Perfornance Level Is Met or Exceeded	55,625
Director [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value Assumptions, Weighted-average Expected Life	0 years	5 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0