SHARE-BASED PAYMENT (Tables)

12 Months Ended

Dec. 31, 2017

SHARE-BASED PAYMENT

Schedule of Stock Compensation Expense

Components of stock compensation expense (in thousands)	2017		2016		2015
Restricted shares	$	12,336	$	10,272	$	8,214
Stock options		1,570		1,768		1,957
2014 PSP		766		3,625		3,913
2016 PSP		4,728		2,812		—
2017 PSP		1,734		—		—
Total stock compensation expense	$	21,134	$	18,477	$	14,084
Excess tax benefit recognized	$	9,545	$	631	$	1,410

Schedule of Restricted Share Activity

		Weighted-
		Average
		Grant-date
Restricted Shares	Shares	Fair Value
Nonvested at January 1, 2017	1,481,483	$	20.71
Granted	385,379		41.15
Vested	(507,442)		20.08
Forfeited	(14,897)		27.67
Nonvested at December 31, 2017	1,344,523	$	26.68

Schedule of Restricted Share Units Activity

		Weighted-
		Average
		Grant-date
Restricted Share Units	Share Units	Fair Value
Nonvested at January 1, 2017	1,164,791	$	19.61
Granted	335,991		41.79
Vested	(579,589)		16.07
Forfeited	(59,875)		16.07
Nonvested at December 31, 2017	861,318	$	30.89

Schedule of Stock Option Activity

				Weighted-
		Weighted-		Average	Aggregate
		Average		Remaining	Intrinsic
		Exercise		Contract Life	Value
Stock Options	Options	Price		(Years)	(in thousands)
Outstanding at January 1, 2017	1,295,375	$	16.97
Granted	112,731		39.82
Exercised	(11,400)		46.98
Forfeited	—		—
Expired	—		—
Outstanding at December 31, 2017	1,396,706	$	18.85	6.3	$	40,018
Exercisable at December 31, 2017	1,061,465	$	16.59	5.7	$	32,812

Schedule of Stock Options Valuation Assumptions

	2017			2016			2015
Estimated option life		6.00 years			6.00 years			6.00 years
Risk free interest rate		2.04	%		1.31	%		1.68	%
Expected volatility		35.34	%		34.42	%		33.48	%
Expected dividend rate		0.00	%		0.00	%		0.00	%
Strike price	$	39.82		$	20.40		$	16.72
Weighted average grant date fair value per share of options granted	$	14.98		$	7.21		$	5.90