Share-based Compensation (Tables)

12 Months Ended

Dec. 31, 2012

Share-based Compensation [Abstract]

Fair Value of Share Options, Valuation Assumptions

	Year ended December 31,
	2011		2012
Risk-free interest rate		2.74% - 3.88%		2.83% - 3.35%
Expected life (years)		5.40 - 6.35		6.35
Volatility		43.10% - 57.70%		46.98% - 74%
Dividend yield		-		-
Fair value of underlying ordinary shares
at the grant date		5.01 - 14.09		11.17 - 14.73
Fair value of the share options at the grant date		2.64 - 8.15		5.50 - 8.31

Schedule of Share Options Roll Forward

				Weighted average
				exercise price
	Number of options			per option
Outstanding at January 1, 2010		896,050		$	15
Granted		5,149,000			2.8
Exercised		-
Forfeited		(131,100	)
Outstanding at December 31, 2010		5,913,950			2.6
Granted		8,294,900			8.1
Exercised		(31,172	)
Expired		(3,499	)
Forfeited		(487,600	)
Outstanding at December 31, 2011		13,686,579			5.8
Granted		4,213,000			11.8
Exercised		(1,615,452	)
Expired		-
Forfeited		(1,136,113	)
Outstanding at December 31, 2012		15,148,014			7.2
Vested and exercisable at December 31, 2012		4,808,547		$	4.3
Vested and expect to vest at December 31, 2012		16,798,137		$	6.9

Summary of Share Options Activities

	Options outstanding							Options exercisable
			Weighted			Aggregate						Aggregate
			average			intrinsic						intrinsic
			remaining	Exercise		value as of				Exercise		value as of
	Number		contractual	price		December 31,		Number		price per		December 31,
	outstanding		term	per option		2012		exercisable		option		2012
June 30, 2009		552,206	6.5 years	$	1.50	$	10,102		371,195	$	1.50	$	6,790
January 1, 2010		53,353	7.0 years	$	2.20		939		40,853	$	2.20		719
July 1, 2010		4,215,907	7.5 years	$	2.80		71,642		2,411,407	$	2.80		40,978
January 1, 2011		3,171,603	8.0 years	$	5.20		46,284		1,439,784	$	5.20		21,011
February 14, 2011		628,000	8.1 years	$	5.20		9,165		103,000	$	5.20		1,503
March 3, 2011		456,460	8.2 years	$	6.00		6,296		60,835	$	6.00		839
July 1, 2011		2,103,578	8.5 years	$	12.94		14,417		338,566	$	12.94		2,320
July 1, 2011		40,000	8.5 years	$	9.67		405		8,000	$	9.67		81
October 1, 2011		242,907	8.7 years	$	10.89		2,162		34,907	$	10.89		311
January 20,2012		1,407,500	9.0 years	$	10.67		12,846		-	$	10.67		-
February 10, 2012		910,000	9.1 years	$	11.35		7,686		-	$	11.35		-
March 1, 2012		33,000	9.2 years	$	14.09		188		-	$	14.09		-
April 15, 2012		148,000	9.3 years	$	14.52		780		-	$	14.52		-
July 15, 2012		389,000	9.5 years	$	10.95		3,439		-	$	10.95		-
July 15, 2012		40,000	9.5 years	$	10.67		365		-	$	10.67		-
October 15, 2012		756,500	9.8 years	$	14.67		3,878		-	$	14.67		-
Total		15,148,014				$	190,594		4,808,547			$	74,552

Schedule of Nonvested Shares Granted

				Weighted average
				fair value per
	Number of			nonvested share
	nonvested shares			at the grant date(i)
Outstanding at January 1, 2010		11,058,219
Granted		1,670,000		$	1.80
Vested		(1,379,985	)
Forfeited		(214,640	)
Outstanding at December 31, 2010		11,133,594
Granted		3,255,976		$	7.76
Vested		(5,824,709	)
Forfeited		(380,610	)
Outstanding at December 31, 2011		8,184,251
Granted		4,845,877		$	12.03
Vested		(3,136,471	)
Forfeited		(1,121,419	)
Outstanding at December 31, 2012		8,772,238
Vested and to be transferred to grantees at
December 31, 2012		15,378,240
Vested and expect to vest at December 31, 2012		24,150,478

(i) The fair value of the underlying ordinary shares is the same as the fair value of the nonvested shares when calculating the weighted average fair value per nonvested share at the grant date.