Stock Compensation Stock Option Activity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding (in shares)	3,304,595	2,519,918	2,544,574
Granted (in shares)	406,875		0
Exercised (in shares)	(421,657)	(42,184)	(17,727)
Canceled (in shares)	(11)	(14)	(6,929)
Outstanding (in shares)	3,289,802	3,304,595	2,519,918	2,544,574
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 12.58	$ 11.90	$ 11.89
Granted, Weighted Average Exercise Price (in dollars per share)		$ 14.63	$ 0.00
Exercised, Weighted Average Exercise Price (in dollars per share)	$ 11.98	$ 12.90	$ 7.86
Cancelled, Weighted Average Exercise Price (in dollars per share)	$ 0.00	$ 0.00	$ 13.67
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 13.41	$ 12.58	$ 11.90	$ 11.89
Outstanding, Weighted Average Remaining Contractual Term	6 years 4 months 24 days	6 years 6 months 18 days	6 years 7 months 6 days	7 years 7 months 6 days
Outstanding, Aggregate Intrinsic Value	$ 25,977	$ 9,959	$ 4,371	$ 11,187
Options exercisable (in shares)	1,522,748	1,866,016	439,277
Common stock fair value	$ 21.31	$ 15.59	$ 13.49