Stock-Based Compensation - Information by Plan (Details)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of plans / awards	10 years
Remaining Shares Available for Grant Under the Plan (in shares)	1,049,414
Outstanding Shares Granted Under the Plan (in shares)	916,043
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of plans / awards	10 years
Stock options | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Stock options | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Stock appreciation rights and performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted to date (in shares)	0
Non-vested restricted stock award | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Non-vested restricted stock award | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
1998 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Initial Shares Available for Grant Under the Plan (in shares)	630,000
Remaining Shares Available for Grant Under the Plan (in shares)	0
Outstanding Shares Granted Under the Plan (in shares)	5,000
1999A Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Initial Shares Available for Grant Under the Plan (in shares)	1,000,000
Remaining Shares Available for Grant Under the Plan (in shares)	0
Outstanding Shares Granted Under the Plan (in shares)	22,500
2002 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Initial Shares Available for Grant Under the Plan (in shares)	1,000,000
Remaining Shares Available for Grant Under the Plan (in shares)	0
Outstanding Shares Granted Under the Plan (in shares)	13,480
2003 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Initial Shares Available for Grant Under the Plan (in shares)	1,000,000
Remaining Shares Available for Grant Under the Plan (in shares)	0
Outstanding Shares Granted Under the Plan (in shares)	77,556
2006 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Initial Shares Available for Grant Under the Plan (in shares)	1,000,000
Remaining Shares Available for Grant Under the Plan (in shares)	2,250
Outstanding Shares Granted Under the Plan (in shares)	201,247
2010 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Initial Shares Available for Grant Under the Plan (in shares)	1,000,000
Remaining Shares Available for Grant Under the Plan (in shares)	49,164
Outstanding Shares Granted Under the Plan (in shares)	509,260
2014 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Initial Shares Available for Grant Under the Plan (in shares)	1,100,000
Remaining Shares Available for Grant Under the Plan (in shares)	998,000
Outstanding Shares Granted Under the Plan (in shares)	87,000