SHARE-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2017

SHARE-BASED COMPENSATION

Summary of share option activity

	Number of shares		Weighted average exercise price		Weighted average remaining contractual life (years)	Aggregate intrinsic value (thousands)
Outstanding at January 1, 2017	5,794,831		US$	30.58
Granted	1,279,872		US$	56.68
Exercised	(2,147,819	)	US$	29.04
Forfeited	(119,902	)	US$	32.64
Outstanding at December 31, 2017	4,806,982		US$	38.17	3.83	US$	109,017
Vested and expected to vest at December 31, 2017	4,560,233		US$	37.86	3.78	US$	104,855
Exercisable at December 31, 2017	2,236,685		US$	30.66	2.65	US$	67,535

Summary of non-vested share option activity

	Number of shares		Weighted average grant-date fair value (per share)
Non-vested at January 1, 2017	2,495,346		US$	10.37
Granted	1,279,872		US$	15.62
Vested	(1,085,019	)	US$	10.50
Forfeited	(119,902	)	US$	10.55
Non-vested at December 31, 2017	2,570,297		US$	12.86
Expected to vest at December 31, 2017	2,323,548		US$	12.88