Stock-Based Compensation (Details) (USD $)	3 Months Ended
	Mar. 31, 2015
LTIP Paragraph 1 [Abstract]
Common stock was authorized for grants under the LTIP	44,550
Weighted-average per share grant date fair value of unvested shares	$ 52.05
LTIP unrecognized compensation expense	$ 3,200,000
Unrecognized compensation cost, period for recognition	through 2017
Fair value pricing model LTIP	Monte-Carlo option pricing model
Stock price on valuation date	$ 47.64
Performance term (in years)	3 years
Quarterly Dividends Paid Per Share	$ 0.465
Expected dividend yield	3.80%
Dividend Discount Factor	0.8966
LTIP Paragraph 2 [Abstract]
Shares Granted Under RSU	28,020
Stock Price On Restricted Stock Unit Grant Date, Minimum	$ 47.64
RSU unrecognized compensation expense	$ 3,300,000
Unrecognized compensation cost, restricted stock units, period for recognition	through 2019