Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2015

Summary of the option activity

A summary of the stock option activity during 2015 is presented in the following table (dollars and shares in thousands, except per share amounts):

				Weighted
		Weighted		Average
		Average		Remaining	Aggregate
	Shares	Exercise		Contractual	Intrinsic
	Under Options	Price		Term (Years)	Value
Outstanding as of January 1, 2015	2,587	$	37.00	5.0	$	19,581
Exercised	(823)		33.52
Cancelled	(2)		42.69
Forfeited	(24)		41.25
Outstanding as of December 31, 2015	1,738		38.58	4.4		4,521
Exercisable as of December 31, 2015	1,368		37.88	3.5		4,521

Summary additional information concerning outstanding and exercisable stock options

The following table summarizes additional information concerning outstanding and exercisable stock options at December 31, 2015 (shares in thousands):

					Currently Exercisable
				Weighted
		Weighted		Average		Weighted
		Average		Remaining		Average
Range of	Shares Under	Exercise		Contractual	Shares Under	Exercise
Exercise Price	Options	Price		Term (Years)	Options	Price
$23.34 - $25.52	166	$	23.34	2.1	166	$	23.34
27.11 -  28.35	156		28.35	2.8	156		28.35
31.95 -  46.92	1,416		41.72	4.8	1,046		41.60
	1,738		38.58		1,368		37.88

Summary of additional information concerning unvested stock options

The following table summarizes additional information concerning unvested stock options at December 31, 2015 (shares in thousands):

		Weighted
	Shares	Average
	Under	Grant Date Fair
	Options	Value
Unvested at January 1, 2015	906	$	4.85
Vested	(512)		5.06
Forfeited	(24)		4.58
Unvested at December 31, 2015	370		4.59

Summary of additional information concerning restricted stock and restricted stock units

The following table summarizes additional information concerning restricted stock and performance restricted stock units at December 31, 2015 (units and shares in thousands):

		Weighted			Weighted
	Restricted	Average			Average
	Stock	Grant Date		Restricted	Grant Date
	Units	Fair Value		Shares	Fair Value
Unvested at January 1, 2015	900	$	40.54	112	$	38.69
Granted	402		48.56	—		—
Vested	(409)		44.79	(76)		37.26
Forfeited	(26)		43.74	—		—
Unvested at December 31, 2015	867		43.34	36		41.77

Common Stock Options

Assumptions used for estimating fair value of stock options using Black-Scholes option valuation model

	2014		2013
Risk-free rate	1.34	%	0.78	%
Expected life (in years)	4.5		4.5
Expected volatility	22.9	%	28.9	%
Expected dividend yield	5.4	%	5.8	%

Restricted Stock and Performance Restricted Stock Units

Assumptions used for estimating fair value of stock options using Black-Scholes option valuation model

	2015		2014
Expected volatility	17.94	%	21.74	%
Risk-free rate	0.33	%	0.22	%
Expected dividend yield	4.79	%	5.61	%