Employee Benefit Plans (Options) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning of year	2,928,312
Granted	0	0	0
Exercised	(479,831)	(674,187)	(801,810)
Forfeited	(15,096)
Expired	(6,711)
Outstanding, end of year	2,426,674	2,928,312
Exercisable, end of year	2,151,790
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning of year - weighted average exercise price	$ 16.07
Granted - weighted average exercise price	$ 0
Exercised - weighted average exercise price	$ (14.25)
Forfeited - weighted average exercise price	$ (20.50)
Expired - weighted average exercise price	$ (16.35)
Outstanding, end of year - weighted average exercise price	$ 16.40	$ 16.07
Exercisable, end of year - weighted average exercise price	$ 15.88
Additional disclosures:
Outstanding, end of year, weighted average contractual term	4 years 8 months 12 days
Exercisable, end of year, weighted average contractual term	4 years 6 months 0 days
Outstanding, end of year, aggregate intrinsic value	$ 52,212
Exercisable, end of year, aggregate intrinsic value	47,424
Weighted average grant date fair value	$ 0	$ 0.00	$ 0.00
Total intrinsic value of options exercised	10,313	12,212	9,650
Proceeds from option exercises	10,027	12,137	10,527
Stock options
Additional disclosures:
Total compensation cost not yet recognized	$ 299
Compensation cost not yet recognized, period for recognition	0 years 1 month 22 days
Life of award	10 years
Vesting period	4 years