STOCK AWARD PLANS - Total Compensation Expense Recognized (Details) - USD ($)	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 11,397,000	$ 17,123,000
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	5,013,000	4,249,000
Stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	5,403,000	11,744,000
Company expense on ESPP discount
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 981,471	$ 1,130,000

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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