Stock Repurchase Program (Details) (USD $)	3 Months Ended		116 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Jul. 26, 2005
Equity [Abstract]
Maximum number of share authorized to repurchase under the program (in shares)				750,000
Common stock purchased during the period (in shares)	2,364	6,855	401,075
Average price per share (in dollars per share)	$ 82.83