Share-Based Payments (Tables)

12 Months Ended

Dec. 31, 2014

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Summary of Stock Option Transactions under Share Based Payment Plans

	Number of Shares	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life in Years	Aggregate Intrinsic Value ($ in thousands)
Outstanding at December 31, 2013	903,439	$	19.75
Granted in 2014	—	—
Exercised in 2014	161,940	20.41
Forfeited or expired in 2014	6,960	28.09
Outstanding at December 31, 2014	734,539	$	19.52	3.42	$	5,695
Exercisable at December 31, 2014	734,539	$	19.52	3.42	$	5,695

Schedule of Summary of Restricted Stock Units Transactions under Share-Based Payment Plans

	Number of Shares	Weighted Average Grant Date Fair Value
Unvested RSU awards at December 31, 2013	1,096,780	$	18.73
Granted in 2014	374,963	21.58
Vested in 2014	378,150	17.47
Forfeited in 2014	16,583	19.19
Unvested RSU awards at December 31, 2014	1,077,010	$	20.18

Schedule of Weighted Average Assumptions for Employee Stock Purchase Plan

	ESPP
	2014		2013	2012
Risk-free interest rate	0.07	%	0.11	0.12
Expected term	6 months		6 months	6 months
Dividend yield	2.0	%	2.4	2.9
Expected volatility	21	%	19	24

Schedule of Weighted-Average Fair Value of Stock Per Share

	2014		2013	2012
RSUs	$	21.58	21.03	17.62
ESPP:
Six month option	1.24		0.97	1.05
Discount of grant date market value	3.87		3.24	2.70
Total ESPP	5.11		4.21	3.75
Agent Plan:
Discount of grant date market value	2.42		2.40	1.76