Subsequent Events (Details) - USD ($)	1 Months Ended
	Feb. 28, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	May 12, 2014
Subsequent Event [Line Items]
Authorized share amount for repurchase		$ 66,000,000	$ 60,000,000	$ 20,000,000	$ 10,000,000
Subsequent Event
Subsequent Event [Line Items]
Increase in authorized share amount for repurchase	$ 20,000,000
Authorized share amount for repurchase	$ 86,000,000