Stock Repurchases (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended	38 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Apr. 30, 2012
Share Purchases [Line Items]
Stock repurchased during period, shares	3,891
Aggregate purchase price of shares repurchased	$ 0.1
Share Repurchase Program Two Thousand and Twelve [Member]
Share Purchases [Line Items]
Stock repurchase program, number of shares authorized to be repurchased			1,000,000
Stock repurchased during period, shares	267,089	1,000,000.0
Average cost per share of shares repurchased	$ 31.18	$ 18.20
Aggregate purchase price of shares repurchased	$ 8.3	$ 18.2
Shares remaining and authorized for repurchase	0	0