Stock-Based Compensation - Additional Information (Details) (Restricted Stock, USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended	12 Months Ended	0 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Nov. 21, 2013
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Restricted shares issued	0
Unrecognized compensation expense	$ 12.7
2014 Long Term Incentive Plan Member
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Restricted shares issued		13,000
Fair value of the Company’s common stock on the date of grant		$ 45.68
1997 Key Employee Stock Option Plan Member
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Restricted shares issued			184,000
Fair value of the Company’s common stock on the date of grant			$ 98.68
Unrecognized compensation expense			$ 17.3
Expected period for recognition of unrecognized compensation expense			4 years