STOCK (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Shareholder Return Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum shares to be awarded in future under share-based compensation plan (in shares)			0
Maximum shares to be awarded in future under share-based compensation plan (in shares)			53,680
Vesting rights for shares to be awarded in future under share-based compensation plan			vest 25% per year on January 1 in years 2012, 2013, 2014 and 2015
Company Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum shares to be awarded in future under share-based compensation plan (in shares)			0
Maximum shares to be awarded in future under share-based compensation plan (in shares)			50,705
Vesting rights for shares to be awarded in future under share-based compensation plan			vest 20% on the date shares are determined and awarded and 20% per year on each January 1 for the subsequent four years
Equity Incentive Plan 2004 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of shares authorized to be issued (in shares)	1,900,000		1,900,000
Total shares available for grant (in shares)	1,406,923		1,406,923
Stock-based compensation cost	$ 554,000	$ 417,000	$ 1,348,000	$ 861,000
Stock-based compensation costs capitalized as part of Company's development costs	47,000	18,000	86,000	29,000
Fair value of shares vested	0		613,000
Shares withheld for tax obligations (in shares)	0		3,564
Restricted Stock Activity [Roll Forward]
Nonvested at Start of period (in shares)	235,162		170,575
Granted (in shares)	0		78,491
Forfeited (in shares)	0		0
Vested (in shares)	0		(13,904)
Nonvested at end of period (in shares)	235,162		235,162
Weighted Average Grant Date Fair Value [Abstract]
Nonvested at beginning of period (per share)	$ 38.89		$ 36.29
Granted (per share)	$ 0.00		$ 45.05
Forfeited (per share)	$ 0.00		$ 0.00
Vested (per share)	$ 0.00		$ 41.77
Nonvested at end of period (per share)	$ 38.89		$ 38.89
Directors Equity Plan 2005 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of shares authorized to be issued (in shares)	50,000		50,000
Stock-based compensation cost	$ 60,000	$ 60,000	$ 120,000	$ 120,000