SHARE-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2019

Schedule of weighted average assumptions used in the BSM pricing model for grants made

		2018		2019
Dividend yield		—		—
Expected annual volatility		39.0	%	39.4-41.1	%
Risk-free interest rate		2.72-2.90	%	1.64-1.88	%
Expected life of the awards (years)		7.07-7.11		5.91-6.05
Weighted-average grant date fair value of awards (per share)	$	14.62	$	15.97

Summary of awards activity for the Company

	Options			SARs			RSUs
		Weighted			Weighted			Weighted
		average exercise			average exercise			average exercise
	Quantity	price per share		Quantity	price per share		Quantity	price per share
Outstanding as of December 31, 2018	3,601,433	$	34.51	154,994	$	32.44	13,865,414	—
Granted	1,068,554		36.62	—		—	5,293,636	—
Exercised	(410,145)		5.86	(28,500)		31.22	(5,218,733)	—
Forfeited	—		—	—		—	(638,743)	—
Cancelled	(945,000)		40.00	(394)		20.99	(500,342)	—
Outstanding as of December 31, 2019	3,314,842	$	37.17	126,100	$	32.75	12,801,232	—

Summary of information about outstanding and exercisable awards

		Awards Outstanding					Awards Exercisable
			Average					Average
			Remaining		Aggregate			Remaining		Aggregate
	Type of	Number	Contractual		Intrinsic		Number	Contractual		Intrinsic
Exercise Price ($)	award	outstanding	Life (in years)		Value		exercisable	Life (in years)		Value
$4.16	Option	48,438	0.47	$		1.9	48,438	0.47	$		1.9
$8.77	Option	128,850	0.89			4.5	128,850	0.89			4.5
$36.62	Option	1,068,554	9.59			7.3	—	—			—
$40.00	Option	2,069,000	8.09			7.2	1,339,000	8.02			4.6
Total Options		3,314,842	8.18			20.9	1,516,288	7.17			11.0
$20.99	SARs	1,100	1.91			—	1,100	1.91			—
$32.85	SARs	125,000	3.56			1.4	125,000	3.56			1.4
Total SARs		126,100	3.55			1.4	126,100	3.55			1.4
Total RSUs	RSU	12,801,232	8.38			556.7	3,565,653	7.22			155.1
Total Options, SARs, RSUs		16,242,174	8.30	$		579.0	5,208,041	7.12	$		167.5

Summary of information about non-vested share awards

	Options			RSUs
		Weighted			Weighted
		Average			Average
		Grant Date			Grant Date
	Quantity	Fair Value		Quantity	Fair Value
Non-vested as of December 31, 2018	2,386,500	$	13.17	8,567,331	$	28.68
Granted	1,068,554		15.97	5,293,636		35.69
Vested	(711,500)		13.41	(3,486,303)		27.13
Forfeited	—		—	(638,743)		31.11
Cancelled	(945,000)		11.86	(500,342)		30.10
Non-vested as of December 31, 2019	1,798,554	$	15.43	9,235,579	$	32.92

2018 plan

Schedule of weighted average assumptions used in the BSM pricing model for grants made

		2019
Dividend yield		—
Expected annual volatility		50.00	%
Risk-free interest rate		7.76-8.88	%
Expected life of the awards (years)		6.06-6.10
Weighted-average grant date fair value of awards (per share)	$	131.25

Summary of awards activity for the Company

	Options			RSUs
		Weighted				Weighted
		average exercise				average exercise
	Quantity	price per share		Quantity		price per share
Outstanding as of December 31, 2018	189	$	80.89	114,499	$	—
Granted	256,812		211.88	191,214		—
Exercised	(67)		80.89	(6,025)		—
Forfeited	(32)		80.89	(10,586)		—
Cancelled	(77,380)		203.83	(17,560)		—
Outstanding as of December 31, 2019	179,522	$	215.28	271,542	$	—

Summary of information about outstanding and exercisable awards

		Awards Outstanding		Awards Exercisable
			Average		Average
			Remaining		Remaining
	Type of	Number	Contractual	Number	Contractual
Exercise Price ($)	award	outstanding	Life (in years)	exercisable	Life (in years)
$80.89	Option	97	8.11	97	8.11
$203.83	Option	139,425	9.15	35,996	9.13
$255.51	Option	40,000	9.61	—	—
Total Options		179,522	9.26	36,093	9.12
Total RSUs	RSU	271,542	8.98	64,735	8.66
Total Options and RSUs		451,064	9.09	100,828	8.83

Summary of information about non-vested share awards

	Options			RSUs
		Weighted			Weighted
		Average			Average
		Grant Date			Grant Date
	Quantity	Fair Value		Quantity	Fair Value
Non-vested as of December 31, 2017	—	$	—	—	$	—
Granted	3,397		126.48	137,998		166.00
Vested	(1,078)		137.62	(13,733)		174.27
Forfeited	(2,224)		120.53	(22,282)		172.06
Cancelled	(26)		157.24	—		—
Non-vested as of December 31, 2018	69	$	132.54	101,983	$	163.40
Granted	256,812		131.25	191,214		218.27
Vested	(36,040)		132.05	(58,244)		179.91
Forfeited	(32)		132.64	(10,586)		193.31
Cancelled	(77,380)		132.07	(17,560)		214.72
Non-vested as of December 31, 2019	143,429	$	130.60	206,807	$	203.59