Share-Based Payments (Tables)

12 Months Ended

Dec. 31, 2015

Share-Based Payments

Schedule of shares available for issuance under the 2013 Plan

        The following table is a roll-forward of shares available for issuance under the 2013 Plan for the period beginning June 11, 2013 through the year ended December 31, 2015 (in thousands):

	Shares Available for Issuance
Shares reserved for issuance at June 11, 2013		3,300
Add:
Stockholder-approved increase in share pool in 2014		1,800
Stockholder-approved increase in share pool in 2015		2,550
Stock options and restricted stock awards forfeited or expired under prior plans		630
Stock options and awards forfeited under 2013 Plan		278
Less:
Stock options and awards granted under 2013 Plan		(4,009	)
Shares reserved for issuance at December 31, 2015		4,549

Summary of share-based compensation expense (income)

        The following table summarizes share-based compensation expense recorded in the years ended December 31, 2015, 2014 and 2013 (in millions):

	2015		2014		2013
Outstanding employee and non-employee stock option grants	$	10.5	$	9.7	$	8.1
Outstanding restricted stock awards		0.5		3.5		4.3
Employee stock purchase plan		0.4		0.4		0.4
Total compensation cost	$	11.4	$	13.6	$	12.8

Schedule of weighted average assumptions

	Weighted Average Assumptions
	Stock Options									Employee Stock Purchase Plan
	2015			2014			2013			2015			2014			2013
Expected volatility		59	%		66	%		63	%		59	%		63	%		64	%
Expected dividends		—			—			—			—			—			—
Expected life (years)		6.1			6.1			6.0			0.5			0.5			0.5
Risk-free interest rate		1.9	%		2.2	%		1.5	%		0.1	%		0.1	%		0.1	%

Schedule of stock option activity of company's stock plan

	Number of Stock Options (in thousands)			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2014		7,110		$	14.43
Granted		1,635			14.61
Exercised		(1,737	)		13.57
Forfeited		(157	)		14.71
Expired		(240	)		18.52
Outstanding at December 31, 2015		6,611		$	14.54		6.45	$	9,041
Exercisable at December 31, 2015		4,211		$	14.09		5.21	$	6,507
Vested or expected to vest at December 31, 2015		6,362		$	14.52		6.35	$	8,777

Schedule of nonvested shares of restricted stock

        A summary of the status of nonvested shares of restricted stock as of December 31, 2015 and the changes during the year then ended are presented below (in thousands, except fair values):

	Number of Shares			Weighted Average Grant Date Fair Value
Nonvested at January 1, 2015		1,174		$	15.15
Granted		255			13.19
Vested		(517	)		15.15
Forfeited		(151	)		14.55
Nonvested at December 31, 2015		761		$	14.61

Summarized information about time-based or performance-based vesting schedules

        Nonvested shares of restricted stock that have time-based or performance-based vesting schedules as of December 31, 2015 are summarized below (in thousands):

Vesting Schedule	Nonvested Shares
Time-based		449
Performance-based		312
Nonvested at December 31, 2015		761