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

12 Months Ended

Dec. 31, 2016

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, 2016:

Performance Share Grants with Performance Conditions
Below threshold performance	—
Threshold performance	133,073
Target performance	293,967
Maximum performance	440,751

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, 2016		December 31, 2015		December 31, 2014
Stock Grants Outstanding Beginning of the Year at Target Achievement	272,353		237,045		265,701
New Stock Grants/Additional shares due to maximum achievement	287,091		114,221		165,996
Vested Grants	(172,749	)	(52,436	)	(41,694	)
Expired/Forfeited Grants	(524	)	(26,477	)	(152,958	)
Stock Grants Outstanding at Target Achievement	386,171		272,353		237,045

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:	December 31, 2016		December 31, 2015		December 31, 2014
Expensed	$	3,847,000	$	2,989,000	$	2,645,000
Capitalized	296,000		165,000		95,000
	4,143,000		3,154,000		2,740,000
NDSI Plan	738,000		768,000		889,000
	$	4,881,000	$	3,922,000	$	3,629,000