Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2019

Performance-based option activity under the 2007 SIP and the 2013 SIP for the period was as follows:

	Shares			Weighted Average Exercise Price (per share)			Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in millions)
Performance-based options outstanding at December 31, 2018		366,377		$	13.50			3.1	$	7.7
Granted		—			—			—		—
Exercised		(43,849	)		(13.64	)		—		—
Forfeited or expired		—			—			—		—
Performance-based options outstanding at March 31, 2019		322,528		$	13.48			2.9	$	12.2
Performance-based options exercisable at March 31, 2019		322,528		$	13.48			2.9	$	12.2

Term-based option activity, including stock options under the 2007 SIP, the 2013 SIP and the 2018 EIP, for the period was as follows:

	Shares			Weighted Average Exercise Price (per share)			Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in millions)
Term-based options outstanding at December 31, 2018		13,549,769		$	19.28			7.5	$	206.8
Granted		4,112,295			49.66			—		—
Exercised		(1,186,362	)		(16.69	)		—		—
Forfeited or expired		(45,530	)		(21.22	)		—		—
Term-based options outstanding at March 31, 2019		16,430,172		$	26.83			8.1	$	402.1
Term-based options exercisable at March 31, 2019		4,960,532		$	16.84			5.6	$	170.9

Restricted stock units (“RSUs”) activity, including RSUs under the 2013 SIP and the 2018 EIP, for the period was as follows:

	Shares
RSUs outstanding at December 31, 2018		664,073
Granted		50,000
Shares issued upon vesting of RSUs		—
Forfeited or canceled		—
RSUs outstanding at March 31, 2019		714,073
RSUs releasable at March 31, 2019		250,000