Share-based Compensation (Stock Option Activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Options, Outstanding [Roll Forward]
Stock options outstanding, ending balance	207,000
Stock options, Exercisable	139,500
Stock Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Stock options, Weighted Average Exercise Price, beginning balance (in dollars per share)	$ 8.28	$ 4.03	$ 2.51
Stock options, Granted, Weighted Average Exercise Price (in dollars per share)	$ 0.00	$ 14.89	$ 16.94
Stock options, Exercised, Weighted Average Exercise Price (in dollars per share)	$ 1.75	$ 1.73	$ 0.75
Stock options, Canceled, Weighted Average Exercise Price (in dollars per share)	$ 17.58	$ 0.00	$ 0
Stock options, Weighted Average Exercise Price, ending balance (in dollars per share)	$ 16.41	$ 8.28	$ 4.03	$ 2.51
Stock options, Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 16.35
Stock Options, Additional Disclosures [Abstract]
Stock options outstanding, Weighted Average Remaining Contractual Term (in years)	1 year 10 months 17 days	1 year	1 year 2 months 1 day	1 year 6 months 21 days
Stock options, Exercisable, Weighted Average Remaining Contractual Term (in years)	1 year 5 months 5 days
Stock options outstanding, Aggregate Intrinsic Value	$ 121,000	$ 5,093,000	$ 24,171,000	$ 64,959,000
Stock options, Exercisable, Aggregate Intrinsic Value	89,000
Proceeds from stock options exercised	788,000	2,161,000	1,020,000
Stock Options
Stock Options, Additional Disclosures [Abstract]
Stock options exercised in period, intrinsic value	$ 5,300,000	$ 11,400,000	$ 24,800,000
Within Plans
Stock Options, Outstanding [Roll Forward]
Stock options outstanding, beginning balance	792,000	1,998,633	3,315,175
Stock options, Granted	0	45,000	45,000
Stock options, Exercised	(450,000)	(1,251,633)	(1,361,542)
Stock options, Canceled	(135,000)	0	0
Stock options outstanding, ending balance	207,000	792,000	1,998,633
Stock options, Exercisable	139,500