Stock Compensation - Restricted Stock and Performance Share Grants (Tables)

12 Months Ended

Dec. 31, 2017

Stock Compensation - Restricted Stock and Performance Share Grants [Abstract]

Summary of performance share grants with performance conditions

The following is a summary of the Company's performance share grants with performance conditions for the year ended December 31, 2017:

Performance Share Grants with Performance Conditions
Below threshold performance	—
Threshold performance	169,178
Target performance	387,886
Maximum performance	589,415

Summary of stock grant activity

The following is a summary of the Company’s stock grant activity, both time and performance unit grants, assuming target achievement for outstanding performance grants for the following twelve-month periods ended:

	December 31, 2017		December 31, 2016		December 31, 2015
Stock Grants Outstanding Beginning of the Year at Target Achievement	386,171		272,353		237,045
New Stock Grants/Additional shares due to achievement in excess of target	295,243		287,091		114,221
Vested Grants	(99,769	)	(172,749	)	(52,436	)
Expired/Forfeited Grants	(44,785	)	(524	)	(26,477	)
Stock Grants Outstanding at Target Achievement	536,860		386,171		272,353

Summary of stock compensation costs for Employee and NDSI Plans

The following table summarizes stock compensation costs for the Company's 1998 Stock Incentive Plan, or the Employee 1998 Plan, and NDSI Plan for the following periods:

Employee 1998 Plan ($ in thousands):	December 31, 2017		December 31, 2016		December 31, 2015
Expensed	$	2,889	$	3,847	$	2,989
Capitalized	555		296		165
	3,444		4,143		3,154
NDSI Plan	663		738		768
	$	4,107	$	4,881	$	3,922