Represents the retirement age of employees specified under the share-based compensation plan.

No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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-Section F

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Stock-Based Compensation (Restricted Stock) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014 Y	Dec. 31, 2013 Y	Dec. 31, 2012 Y	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	145,149
Expense (Income)	$ 1,114,000	$ 0	$ 0
Restricted stock unit activity
Nonvested at the beginning of the period (in shares)	0
Granted (in shares)	145,149
Vested (in shares)	(1,784)
Forfeited (in shares)	(9,796)
Nonvested at the end of the period (in shares)	133,569	0
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	227,672	216,869	172,104
Granted (in dollars per share)	$ 25.14	$ 20.62	$ 19.23
Expense (Income)	2,513,000	1,976,000	1,420,000
Restricted stock unit activity
Nonvested at the beginning of the period (in shares)	213,841.000	141,473.000	62,641
Granted (in shares)	227,672	216,869	172,104
Vested (in shares)	(52,041)	(69,955)	(67,861)
Forfeited (in shares)	(84,956)	(74,546)	(25,411)
Nonvested at the end of the period (in shares)	304,516.000	213,841.000	141,473.000
Weighted Average Grant-Date Fair Value
Nonvested at the beginning of the period (in dollars per share)	$ 19.95	$ 19.19	$ 25.39
Granted (in dollars per share)	$ 25.14	$ 20.62	$ 19.23
Vested (in dollars per share)	$ 23.58	$ 20.54	$ 24.86
Forfeited (in dollars per share)	$ 20.92	$ 22.61	$ 20.35
Nonvested at the end of the period (in dollars per share)	$ 22.94	$ 19.95	$ 19.19
Additional disclosures
Unrecognized stock-based compensation expense	4,000,000
Unrecognized stock-based compensation expense, period of recognition	2 years 1 month
2013 Equity and Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares authorized for issuance	6,800,000
Number of shares available for grant	5,616,343
2013 Equity and Incentive Compensation Plan \| Equity Awards, Other Than Options And Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares authorized for issuance	3,400,000
Number of shares available for grant	3,013,373
1995 Non-Employee Directors' Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares authorized for issuance	600,000
Number of shares available for grant	107,063
1995 Non-Employee Directors' Stock Plan \| Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
Granted (in shares)	36,840	46,287	30,618	20,192
Granted (in dollars per share)	$ 24.80	$ 20.60	$ 21.44	$ 34.79
Restricted stock unit activity
Granted (in shares)	36,840	46,287	30,618	20,192
Weighted Average Grant-Date Fair Value
Granted (in dollars per share)	$ 24.80	$ 20.60	$ 21.44	$ 34.79
1995 Non-Employee Directors' Stock Plan \| Restricted stock units \| 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense (Income)	0	0	234,000
1995 Non-Employee Directors' Stock Plan \| Restricted stock units \| 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense (Income)	0	255,000	402,000
1995 Non-Employee Directors' Stock Plan \| Restricted stock units \| 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense (Income)	318,000	636,000	0
1995 Non-Employee Directors' Stock Plan \| Restricted stock units \| 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense (Income)	602,000	0	0
1995 Executive Incentive Compensation Plan \| Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years	3 years	3 years
Retirement age of employees (in years)	62	62	62
Granted (in shares)	190,832	170,582	141,486	17,250	26,000	121,625
Granted (in dollars per share)	$ 25.21	$ 20.63	$ 18.75	$ 23.55	$ 23.78	$ 25.98
Restricted stock unit activity
Granted (in shares)	190,832	170,582	141,486	17,250	26,000	121,625
Weighted Average Grant-Date Fair Value
Granted (in dollars per share)	$ 25.21	$ 20.63	$ 18.75	$ 23.55	$ 23.78	$ 25.98
1995 Executive Incentive Compensation Plan \| Restricted stock units \| 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense (Income)	0	0	43,000
1995 Executive Incentive Compensation Plan \| Restricted stock units \| 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense (Income)	0	0	21,000
1995 Executive Incentive Compensation Plan \| Restricted stock units \| 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense (Income)	3,000	69,000	195,000
1995 Executive Incentive Compensation Plan \| Restricted stock units \| 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense (Income)	151,000	383,000	525,000
1995 Executive Incentive Compensation Plan \| Restricted stock units \| 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense (Income)	$ 325,000	$ 633,000	$ 0