Debt (Details)	3 Months Ended
	Mar. 31, 2016 USD ($)	Mar. 01, 2016 USD ($)	Apr. 23, 2012 USD ($)
Secured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 400,000,000
Line Of Credit Facility Term	5 years
Line Of Credit Facility Additional Borrowing Capacity		50,000,000
Long-term Line of Credit		$ 107,000,000
Line of credit facility, covenant terms, maximum debt to EBITDA ratio	4.00
Line of credit facility, covenant terms, minimum adjusted EBIT-to-interest expense ratio	2.50
Line Of Credit Facility, Covenant Terms, Maximum Aggregate Dividends	$ 100,000
Line of credit facility, covenant terms, percentage of shareholders' equity to net income	50.00%
Credit Spread Over London Interbank Offered Rate Basis Points	1.75%
Credit Facility covenant leverage ratio three times limitation	3.00
Credit Facility limitation on dividend payments at leverage ratio greater than 3.00x	$ 4,000,000
Credit Facility, covenants, 50% of net income limitation when leverage ratio exceeds 3.00x	50.00%
Credit Facility covenant three point five times leverage ratio	350.00%
Credit Facility fixed charge coverage one pt two ratio limitation	120.00%
Unsecured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			$ 350,000,000
Indebtedness To Adjusted Ebitda Ratio Greater Than Three Point Five But Less Than Or Equal To Four [Member]
Line of Credit Facility [Line Items]
Credit Spread Over London Interbank Offered Rate Basis Points	2.50%
Line of Credit Facility, Commitment Fee Percentage	0.45%
Indebtedness To Adjusted Ebitda Ratio Greater Than Three But Less Than Or Equal To Three Point Five [Member]
Line of Credit Facility [Line Items]
Credit Spread Over London Interbank Offered Rate Basis Points	2.25%
Line of Credit Facility, Commitment Fee Percentage	0.40%
Indebtedness To Adjusted Ebitda Ratio Greater Than Two But Less Than Or Equal To Three [Member]
Line of Credit Facility [Line Items]
Credit Spread Over London Interbank Offered Rate Basis Points	2.00%
Line of Credit Facility, Commitment Fee Percentage	0.35%
Indebtedness To Adjusted Ebitda Ratio Greater Than One But Less Than Or Equal To Two [Member]
Line of Credit Facility [Line Items]
Credit Spread Over London Interbank Offered Rate Basis Points	1.75%
Line of Credit Facility, Commitment Fee Percentage	0.30%
Indebtedness To Adjusted Ebitda Ratio Less Than Or Equal To One [Member]
Line of Credit Facility [Line Items]
Line Of Credit Facility Covenant Terms Debt To Ebitda Ratio	1.0
Credit Spread Over London Interbank Offered Rate Basis Points	1.50%
Line of Credit Facility, Commitment Fee Percentage	0.25%
Minimum | Indebtedness To Adjusted Ebitda Ratio Greater Than Three Point Five But Less Than Or Equal To Four [Member]
Line of Credit Facility [Line Items]
Line Of Credit Facility Covenant Terms Debt To Ebitda Ratio	3.5
Minimum | Indebtedness To Adjusted Ebitda Ratio Greater Than Three But Less Than Or Equal To Three Point Five [Member]
Line of Credit Facility [Line Items]
Line Of Credit Facility Covenant Terms Debt To Ebitda Ratio	3.0
Minimum | Indebtedness To Adjusted Ebitda Ratio Greater Than Two But Less Than Or Equal To Three [Member]
Line of Credit Facility [Line Items]
Line Of Credit Facility Covenant Terms Debt To Ebitda Ratio	2.0
Minimum | Indebtedness To Adjusted Ebitda Ratio Greater Than One But Less Than Or Equal To Two [Member]
Line of Credit Facility [Line Items]
Line Of Credit Facility Covenant Terms Debt To Ebitda Ratio	1.0
Maximum | Indebtedness To Adjusted Ebitda Ratio Greater Than Three Point Five But Less Than Or Equal To Four [Member]
Line of Credit Facility [Line Items]
Line Of Credit Facility Covenant Terms Debt To Ebitda Ratio	4.0
Maximum | Indebtedness To Adjusted Ebitda Ratio Greater Than Three But Less Than Or Equal To Three Point Five [Member]
Line of Credit Facility [Line Items]
Line Of Credit Facility Covenant Terms Debt To Ebitda Ratio	3.5
Maximum | Indebtedness To Adjusted Ebitda Ratio Greater Than Two But Less Than Or Equal To Three [Member]
Line of Credit Facility [Line Items]
Line Of Credit Facility Covenant Terms Debt To Ebitda Ratio	3.0
Maximum | Indebtedness To Adjusted Ebitda Ratio Greater Than One But Less Than Or Equal To Two [Member]
Line of Credit Facility [Line Items]
Line Of Credit Facility Covenant Terms Debt To Ebitda Ratio	2.0