Stock-Based Compensation Plans - Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Shares of Restricted Options
Beginning balance (in shares)	166,872	168,963
Granted (in shares)	223,186
Exercised (in shares)	(2,525)	0	0
Forfeited or expired (in shares)	(53,554)
Ending balance (in shares)	333,979	166,872	168,963
Exercisable (in shares)	78,806
Vested and expected to vest (in shares)	78,806
Weighted Average Fair Value at Date of Grant
Beginning balance (in dollars per share)	$ 23.58
Granted (in dollars per share)	28.44
Exercised (in dollars per share)	23.58
Forfeited or expired (in dollars per share)	25.98
Ending balance (in dollars per share)	26.44	$ 23.58
Exercisable (in dollars per share)	25.75
Vested and expected to vest (in dollars per share)	$ 25.75