STOCK-BASED COMPENSATION - Non-Qualified Stock Option Awards Granted (Details) - Stock Option Awards - Amended and Restated 2010 Equity Incentive Plan - $ / shares							12 Months Ended
	Aug. 04, 2017	Feb. 26, 2016	Jun. 29, 2015	May 20, 2015	Feb. 09, 2015	Oct. 22, 2014	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock-based compensation
Granted (in shares)							0
Exercised (in shares)							0	10,000	23,500
Mr. Albright
Stock-based compensation
Granted (in shares)		40,000		40,000	20,000
Period of expiration after death or termination for disability		12 months			12 months
Period of expiration after termination of employment for reason other than death or disability		30 days			30 days
Exercise price (in dollars per share)				$ 55.62	$ 57.50
Mr. Smith
Stock-based compensation
Granted (in shares)						10,000
Vesting per year (as a percent)						33.00%
Period of expiration from grant date						10 years
Period of expiration after death or termination for disability						12 months
Period of expiration after termination of employment for reason other than death or disability						30 days
Exercise price (in dollars per share)						$ 50.00
Officer
Stock-based compensation
Granted (in shares)			10,000
Vesting per year (as a percent)			33.00%
Period of expiration after death or termination for disability			12 months
Period of expiration after termination of employment for reason other than death or disability			30 days
Exercise price (in dollars per share)			$ 57.54
Equity Award Agreements
Award agreements
Period after change of control for equity award to fully vest upon termination of employment without cause or resignation	24 months