Stock-Based Compensation Plans (Tables)

3 Months Ended

Mar. 31, 2013

Summary of Stock Options Issued Pursuant to Stock Incentive Plans

A summary of stock options issued pursuant to the Company’s stock incentive plans is as follows:

	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value of In-the-Money Options
Outstanding as of December 31, 2012		2,968,582		$	27.15
Granted		18,359			47.63
Exercised		(169,605	)		22.78
Expired		(429	)		28.94
Outstanding as of March 31, 2013		2,816,907		$	27.55		5.23	$	60,039,934
Exercisable as of March 31, 2013		1,683,640		$	24.63		4.46	$	40,792,908

Estimated Fair Value of Options Granted using Black-Scholes Option-Pricing Model with Weighted-Average Assumptions

The fair value of options granted during the three months ended March 31, 2013 and 2012 was estimated on the date of grant using the Black-Scholes option-pricing model, a pricing model acceptable under U.S. GAAP, with the following weighted-average assumptions:

	Three Months Ended			Three Months Ended
	March 31, 2013			March 31, 2012
Expected life (years)		5.55			5.55
Interest rate		0.8	%		1.1	%
Volatility		50.0	%		51.3	%
Dividend yield		—			—

Summary of Nonvested Long-Term Incentive Program Performance Share Awards Outstanding and Changes During Period

A summary of nonvested long-term incentive program performance share awards (“LTIP performance shares”) outstanding as of March 31, 2013 and changes during the period are as follows:

Nonvested LTIP Performance Shares	Number of Shares at Expected Attainment			Weighted- Average Grant Date Fair Value
Nonvested as of December 31, 2012		1,101,484		$	28.14
Granted		14,686			47.63
Vested		(327,576	)		16.83
Nonvested as of March 31, 2013		788,594		$	33.20

Summary of Nonvested Restricted Share Awards and Changes During Period

A summary of nonvested restricted share awards (“RSAs”) as of March 31, 2013 and changes during the period are as follows:

Nonvested Restricted Share Awards	Number of Restricted Share Awards			Weighted-Average Grant Date Fair Value
Nonvested as of December 31, 2012		69,238		$	41.02
Granted		1,000			47.63
Vested		(3,333	)		20.76
Nonvested as of March 31, 2013		66,905		$	42.13

ORCC

Summary of Stock Options Issued Pursuant to Stock Incentive Plans

A summary of transaction stock options issued pursuant to the Company’s stock incentive plans is as follows:

	Number of Shares		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value of In-the-Money Options
Outstanding as of December 31, 2012		—	$	—
Transaction stock options converted upon acquisition of ORCC		37,468		91.92
Outstanding as of March 31, 2013		37,468	$	91.92		2.30	$	61,350
Exercisable as of March 31, 2013		37,468	$	91.92		2.30	$	61,350

S1 2003 Stock Incentive Plan

Summary of Nonvested Restricted Share Awards and Changes During Period

A summary of nonvested Transaction RSAs issued under the S1 2003 Stock Incentive Plan as of March 31, 2013 and changes during the period are as follows:

Nonvested Transaction Restricted Share Awards	Number of Restricted Share Awards			Weighted-Average Grant Date Fair Value
Nonvested as of December 31, 2012		50,244		$	35.41
Forfeited		(3,585	)		35.41
Nonvested as of March 31, 2013		46,659		$	35.41