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Deferred compensation arrangement with individual increase in compensation expense.

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'Maximum participant contribution, expressed as a dollar amount.

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Maximum participant contribution, expressed as a percentage of their compensation.

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Number of shares to be issued under deferred compensation plan included in shares outstanding.

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Share based compensation arrangement by share based payment award terms of purchase common shares under ESPP.

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Voluntary termination of employment age limit.

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Voluntary termination of employment terms.

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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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Amount of discretionary contributions made by an employer to a defined contribution plan.

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Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

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The per share amount of a dividend declared, but not paid, as of the financial reporting date.

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

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Unrecognized cost of unvested share-based compensation awards.

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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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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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Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

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Discount rate from fair value on purchase date that participants pay for shares.

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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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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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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Number of options outstanding, including both vested and non-vested options.

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Amount of capitalized and expensed compensation cost from equity-based compensation arrangements.

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Number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of any shares forfeited. Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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Aggregate change in value for stock issued during the period as a result of employee stock purchase plan.

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Share Based Compensation, 401(k) Plan and Deferred Compensation (Textual) (Details) - USD ($)				12 Months Ended
	May. 28, 2015	Mar. 10, 2015	Feb. 01, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 23, 2015	Feb. 06, 2015	Mar. 12, 2014	Mar. 11, 2014	Feb. 25, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number				2,624,067	2,684,795
Stock-based compensation expense				$ 7,300,000	$ 6,100,000	$ 8,300,000
Stock-based compensation expense, capitalized				1,900,000	1,700,000	1,400,000
Defined Contribution Plan, Employer Discretionary Contribution Amount				$ 400,000	$ 400,000	400,000
Defined Contribution Plan, Maximum Annual Contribution Per Employee, Percent				100.00%
Common shares issued for share based compensation				5,097
Number of shares to be issued under deferred compensation plan included in total shares outstanding				700,000	400,000
Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number				2,624,067
Stock-based compensation expense				$ 0	$ 0	700,000
Stock-based compensation expense, capitalized				0	0	100,000
Restricted Share Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense				$ 2,400,000	$ 2,700,000	3,200,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number				506,147	540,066
Vesting period				3 years
Unrecognized compensation expenses				$ 2,400,000
Weighted average period over which options will be recognized				1 year 7 months 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost				$ 700,000	$ 600,000	600,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				three years from the initial grant dates
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				186,791
Voluntary Termination Of Employment Terms				after reaching at least age 57 and accumulating at least 15 years of service with the Company
Accumulated Service Period For Voluntary Termination				15 years
Restricted Share Awards [Member] \| Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Voluntary Termination of Employment Age Limit				57 years
Restricted Share Awards [Member] \| Cliff Vest After Three Years [Member] \| Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		119,136
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights				after three years from the grant date
Share-based Compensation Arrangement by Share-based Payment Award, Cliff Vesting, Minimum				3 years
Restricted Share Awards [Member] \| Vest Ratably Over Three Years [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	34,006
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights				ratably over three years
Restricted Share Awards [Member] \| Vest Ratably Over Three Years [Member] \| Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		2 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		33,649
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights				ratably over two years
Restricted Performance Share Units Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense				$ 4,200,000	3,200,000	4,400,000
Unrecognized compensation expenses				$ 2,000,000
Weighted average period over which options will be recognized				1 year
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost				$ 1,200,000	$ 1,100,000	800,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				3 year
Common shares issued for share based compensation			486,056
Dividends Payable, Amount Per Share								$ 0.15
Restricted Performance Share Units Plan [Member] \| Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number				555,589	392,014
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				186,395
Aggregate share-based awards awarded to executives							186,395		61,720	134,284	231,093
Restricted Performance Share Units Plan [Member] \| Cliff Vest After Three Years [Member] \| Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights				three year cliff vesting period
Employee Share Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense				$ 100,000	$ 100,000	100,000
Share purchases made by employees under ESPP				85% of the average closing price per share for a specified period
Maximum participant contribution, percentage of compensation				20.00%
Maximum participant contribution, dollar amount				$ 50,000
Aggregate share-based awards awarded to executives				1,250,000
Stock Issued During Period, Value, Employee Stock Purchase Plan				$ 500,000	400,000	400,000
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date				15.00%
Deferred Compensation Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Deferred compensation arrangement with individual increase in compensation expense.				$ 0	$ 0	$ 200,000