Stock-Based Compensation (Table)

12 Months Ended

Dec. 31, 2014

Stock-based compensation

Stock-based compensation, fair value assumptions

	2014	2013	2012
Expected life	4.5 years	4.6-9.0 years	4.5 years
Expected annual volatility rate	28.0%-28.1%	29.2%-39.6%	40.7%-42.6%
Dividend yield	0%	0%	0%
Risk-free interest rate	1.4%-1.5%	0.7%-2.4%	0.5%-0.9%
Estimated annual forfeiture rate	9.4%	0.0%-8.1%	0.0%-9.1%

Summary of stock options

Common Share Options		Number of Options	Weighted Average Exercise Price		Weighted Average Grant Date Fair Value		Aggregate Intrinsic Value		Weighted Average Remaining Contractual Life (in years)
Outstanding at December 31, 2011		2,834,000	$	43.07
(1,533,000 exercisable)				46.23
	Granted	677,000		34.91	$	12.61
	Exercised	(47,000)		29.82			$	205,000
	Forfeited	(117,000)		38.45
	Expired	(133,000)		46.17
Outstanding at December 31, 2012		3,214,000	$	41.58
(1,928,000 exercisable)				43.99
	Granted	1,213,000		32.45	$	11.53
	Exercised	(892,000)		34.78			$	6,787,000
	Forfeited	(574,000)		34.17
	Expired	(247,000)		48.35
Outstanding at December 31, 2013		2,714,000	$	42.22
(1,359,000 exercisable)			$	46.91
	Granted	1,116,000		41.21	$	10.68
	Exercised	(233,000)		32.80			$	1,966,000
	Forfeited	(144,000)		35.09
	Expired	(65,000)		45.68
Outstanding at December 31, 2014		3,388,000	$	41.51			$	7,495,000	6.70
(1,586,000 exercisable)			$	45.28			$	2,984,000	4.40

Summary of nonvested restricted stock units

Common Restricted Stock Units	Number	Weighted Average Grant Date Fair Value
Nonvested at December 31, 2013	1,170,000	$	36.46
Granted	370,000		41.24
Vested	(274,000)		41.92
Forfeited	(124,000)		34.38
Nonvested at December 31, 2014	1,142,000	$	35.60

Stock-based compensation

Year Ended December 31,	2014		2013		2012
(Dollars in thousands)
Stock option awards	$	9,513	$	5,810	$	8,471
Restricted stock unit awards		12,125		9,485		12,300
Deferred compensation bonus and matching stock unit awards		185		2		240
Awards under Non-Employee Director compensation plan		560		547		455
Total stock-based compensation, before income taxes		22,383		15,844		21,466
Income tax benefit		(8,454)		(5,984)		(8,121)
Total stock-based compensation expense, net of income taxes	$	13,929	$	9,860	$	13,345

Stock-based compensation, allocation by financial statement line item

December 31,		2014		2013		2012
(Dollars in thousands)
Selling, general and administrative expense	$	19,429	$	12,933	$	18,437
System operations		2,954		2,911		3,029
Total stock-based compensation expense	$	22,383	$	15,844	$	21,466