Employee Benefit Plans (Tables)

The Company values share options issued with a Black-Scholes valuation model and used the following assumptions:



	Year Ended December 31,
	2011
Expected term of option	5.5 years
Weighted average risk-free interest rate	2.33	%
Weighted average expected volatility	31.51	%
Dividend yield	1.00	%

The following table summarizes the activity related to options granted and exercised:



	Year Ended December 31,
	2013		2012		2011
Options granted	—		—		494,885
Weighted average grant date fair value	$	—	$	—	$	18.27
Options exercised	224,729		267,270		179,807
Total intrinsic value of options exercised	$	12,212	$	9,650	$	4,070
Proceeds from option exercises	$	12,137	$	10,527	$	6,837

The activity related to the Company’s share options is as follows:



	Year Ended December 31, 2013
	Options		Weighted Average Exercise Price			Weighted Average Contractual Term	Aggregate Intrinsic Value
Outstanding at beginning of year	1,224,607		$	47.02
Granted	—		$	—
Exercised	(224,729	)	$	(40.70	)
Forfeited	(23,774	)	$	(57.29	)
Expired	—		$	—
Outstanding at end of year	976,104		$	48.22		5.4 years	$	63,047
Exercisable at end of year	723,416		$	44.79		4.9 years	$	49,207

The activity related to the Company’s LTIP awards is as follows:



	Year Ended December 31, 2013
	Number of Awards		Weighted Average Grant Date Fair Value			Aggregate Intrinsic Value
Outstanding LTIP awards at beginning of year	28,889		$	43.27
Additional LTIP awards granted due to achievement of performance criteria	14,445		43.27
LTIP fully vested	(43,334	)	(43.27		)
Outstanding LTIP at end of year	—		$	—		$	—

The following table shows the total stock-related compensation expense relating to the stock options, RSUs, LTIP and cash equivalent awards.



	Year Ended December 31,
	2013		2012		2011
Stock Options	$	3,269	$	4,256	$	4,098
RSUs and performance-based equity awards	10,700		13,010		13,140
LTIP(1)	—		376		5,056
Cash-equivalent stock awards	50,878		32,760		20,295
Total	$	64,847	$	50,402	$	42,589


(1)	Includes nil, $2,194 and $3,219 related to the DPUI LTIP for the years ended December 31, 2013, 2012 and 2011, respectively.

Rsus Other Than Performance Based Rsus [Member]

The activity related to the Company’s RSUs awards is as follows:



	Year Ended December 31, 2013
	Number of Awards		Weighted Average Grant Date Fair Value			Aggregate Intrinsic Value
Outstanding at beginning of year	135,123		$	46.79
RSUs granted	5,298		87.73
RSUs forfeited	(7,220	)	(38.88		)
RSUs fully vested	(85,302	)	(41.63		)
Outstanding at end of year	47,899		$	65.07		$	5,403

Performance Based Rsus [Member]

The activity related to the Company’s performance-based equity awards is as follows:



	Year Ended December 31, 2013
	Number of Awards		Weighted Average Grant Date Fair Value			Aggregate Intrinsic Value
Outstanding at beginning of year	442,639		$	54.32
Performance-based equity awards granted	65,523		87.73
Additional awards granted due to achievement of performance criteria	7,083		46.05
Performance-based equity awards forfeited	(3,889	)	(62.91		)
Performance-based equity awards fully vested	(243,183	)	(46.05		)
Outstanding at end of year	268,173		$	69.64		$	30,253

Cash Equivalent Stock Awards [Member]

The activity related to the Company's cash-equivalent RSUs and performance-based equity awards is as follows:



	RSU's					Performance-based Awards
Year Ended December 31, 2013	Number of Awards		Weighted Average Grant Date Fair Value			Number of Awards		Weighted Average Grant Date Fair Value
Outstanding at beginning of year	610,537		$	59.86		407,504		57.26
Granted	337,002		87.77			98,279		87.73
Additional awards granted due to achievement of performance criteria	—		—			4,722		46.05
Forfeited	(51,223	)	(69.40		)	(4,396	)	(63.37		)
Fully vested	(213,288	)	(56.08		)	(162,122	)	(46.05		)
Outstanding at end of year	683,028		$	74.10		343,987		$	71.02