Employee Stock Benefit Plans (Stock Appreciation Right Activity) (Details) (Stock Appreciation Rights (SARs), USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding balance at beginning of period	250,979	6,750
Granted	2,600	244,229
Exercised	(6,475)
Canceled	(2,875)
Outstanding balance at end of period	244,229	250,979
Exercisable balance at end of period	0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, weighted-average exercise price, balance at beginning of period (in USD per share)	$ 21.07	$ 14.37
Granted, weighted-average exercise price (in USD per share)	$ 23.02	$ 21.26
Exercised, weighted-average exercise price (in USD per share)	$ 14.98
Canceled, weighted-average exercise price (in USD per share)	$ 16.99
Outstanding, weighted-average exercise price, balance at end of period (in USD per share)	$ 21.27	$ 21.07
Outstanding, weighted-average remaining contractual life	9 years	10 years
Outstanding, aggregate intrinsic value	$ 2,483	$ 0