Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

Share-based Compensation Arrangement [Line Items]

Summary of the company's option activity

	Number of Options
Outstanding as of January 1, 2013	5,829,945
Granted	1,338,360
Exercised	(149,926)
Forfeited	-
Expired	-
Outstanding as of March 31, 2013	7,018,379

Assumptions used to determine the grant date fair value for options granted

Range of risk-free interest rate	0.75% - 0.90%
Weighted average risk-free interest rate	0.90%
Expected life of option grants	4.4 years
Range of expected volatility of underlying stock price	33.83% - 36.09%
Weighted average expected volatility of underlying stock price	33.84%
Expected annual dividends	1.50%

Summary of the company's restricted stock unit activity

	Number of Units
Outstanding as of January 1, 2013	1,968,553
Granted	774,020
Vested	(753,915)
Forfeited	(24,932)
Outstanding as of March 31, 2013	1,963,726