STOCKHOLDERS' EQUITY: Future expense, by award type (Details) $ in Millions	Jun. 30, 2019 USD ($)
Share-based compensation
Future expense for performance stock option units	$ 183.1
2020
Share-based compensation
Future expense for performance stock option units	54.4
2021
Share-based compensation
Future expense for performance stock option units	59.9
2022
Share-based compensation
Future expense for performance stock option units	48.5
2023
Share-based compensation
Future expense for performance stock option units	18.5
2024
Share-based compensation
Future expense for performance stock option units	1.8
Stock options
Share-based compensation
Share-based compensation not yet recognized	1.9
Stock options | 2020
Share-based compensation
Share-based compensation not yet recognized	1.4
Stock options | 2021
Share-based compensation
Share-based compensation not yet recognized	0.5
Stock options | 2022
Share-based compensation
Share-based compensation not yet recognized	0.0
Stock options | 2023
Share-based compensation
Share-based compensation not yet recognized	0.0
Stock options | 2024
Share-based compensation
Share-based compensation not yet recognized	0.0
Restricted stock units
Share-based compensation
Future share-based compensation expense expected	137.9
Restricted stock units | 2020
Share-based compensation
Future share-based compensation expense expected	41.2
Restricted stock units | 2021
Share-based compensation
Future share-based compensation expense expected	43.6
Restricted stock units | 2022
Share-based compensation
Future share-based compensation expense expected	32.8
Restricted stock units | 2023
Share-based compensation
Future share-based compensation expense expected	18.5
Restricted stock units | 2024
Share-based compensation
Future share-based compensation expense expected	1.8
Pacific Data Partners, LLC Agreement Plan | Pacific Data Partners LLC
Share-based compensation
Future share-based compensation expense expected	43.3
Pacific Data Partners, LLC Agreement Plan | Pacific Data Partners LLC | 2020
Share-based compensation
Future share-based compensation expense expected	11.8
Pacific Data Partners, LLC Agreement Plan | Pacific Data Partners LLC | 2021
Share-based compensation
Future share-based compensation expense expected	15.8
Pacific Data Partners, LLC Agreement Plan | Pacific Data Partners LLC | 2022
Share-based compensation
Future share-based compensation expense expected	15.7
Pacific Data Partners, LLC Agreement Plan | Pacific Data Partners LLC | 2023
Share-based compensation
Future share-based compensation expense expected	0.0
Pacific Data Partners, LLC Agreement Plan | Pacific Data Partners LLC | 2024
Share-based compensation
Future share-based compensation expense expected	$ 0.0