Stock-Based Compensation (Summary of Company's SARs Activity) (Details) - SARs [Member] - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance	353,955
Exercised, Shares	(37,834)
Forfeits	(1,204)
Ending balance	314,917	353,955
Exercisable, Shares	262,410
Outstanding, Weighted Average Exercise Price	$ 35.52
Exercised, Weighted Average Exercise Price	28.56
Forfeits, Weighted Average Exercise Price	53.96
Outstanding, Weighted Average Exercise Price	36.28	$ 35.52
Exercisable, Weighted Average Exercise Price	$ 33.30
SharebasedCompensationArrangementsBySharebasedPaymentAwardOptionOutstandingWeightedAverageRemainingContractualTerm	6 years 5 months 12 days	6 years 9 months 7 days
SharebasedCompensationArrangementsBySharebasedPaymentAwardOptionOutstandingWeightedAverageRemainingContractualTerm	6 years 5 months 12 days	6 years 9 months 7 days
Exercisable, Average Remaining Contractual Term Years	6 years 1 month 10 days
Outstanding, Aggregate Intrinsic Value	$ 6,277
Outstanding, Aggregate Intrinsic Value	6,279	$ 6,277
Exercisable, Aggregate Intrinsic Value	$ 6,014