Long-Term Debt and Credit Arrangements (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Total debt	$ 278,115,000	$ 290,130,000
Less: current maturities	1,247,000	19,060,000
Total long-term debt (noncurrent)	276,868,000	271,070,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term Debt, Maturities, Repayments of Principal in 2012	1,200,000
Long-term Debt, Maturities, Repayments of Principal in 2013	41,200,000
Long-term Debt, Maturities, Repayments of Principal in 2014	115,500,000
Long-term Debt, Maturities, Repayments of Principal in 2015	40,000,000
Long-term Debt, Maturities, Repayments of Principal in 2016	40,000,000
Long-term Debt, Maturities, Repayments of Principal thereafter	40,000,000
Letters of Credit Outstanding, Amount	10,100,000
Covenant Compliance	We were in compliance with the covenants contained in our senior note agreements and Credit Agreement.
Institutional Groups One and Two (As Amended March 2014) [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Consolidated Leverage Ratio, Covenant	3.75
Consolidated Leverage Ratio, Maximum, Quarter Ending June 30, 2014	3.50
Consolidated Leverage Ratio, Maximum, Quarter Ending September 30, 2014	3.25
Consolidated Leverage Ratio, Maximum, After Quarter Ending September 30, 2014	3.00
Senior notes payable [Member]
Debt Instrument [Line Items]
Total debt	200,000,000	208,333,000
Proceeds from Lines of Credit	70,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Line of Credit Facility, Amount Outstanding	70,000,000	70,000,000
Senior notes payable [Member] | Institutional Group Two [Member]
Debt Instrument [Line Items]
Total debt	200,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	6.11%
Mortgages payable [Member]
Debt Instrument [Line Items]
Total debt	7,967,000	11,629,000
Mortgages payable [Member] | Real Estate Entities [Member]
Debt Instrument [Line Items]
Total debt	7,900,000
Less: current maturities	1,200,000
Total long-term debt (noncurrent)	6,700,000
Other notes payables [Member]
Debt Instrument [Line Items]
Total debt	148,000	168,000
Line of Credit [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Line of Credit Facility, Maximum Borrowing Capacity	215,000,000
Line of Credit Facility, Remaining Borrowing Capacity	134,900,000
Debt Instrument, Basis Spread on Variable Rate	2.50%
Debt Instrument, Basis Spread on Variable Rate, LIBOR Loans	1.50%
Consolidated Fixed Charge Coverage Ratio, Minimum, Collateral Release Period	1.25
Consolidated Leverage Ratio, Maximum, Collateral Release Period	2.50
Line of Credit [Member] | Minimum [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Line of Credit Facility, Interest Rate at Period End	2.75%
Line of Credit [Member] | Maximum [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Line of Credit Facility, Interest Rate at Period End	4.75%
Line of Credit [Member] | Institutional Groups One and Two (As Amended March 2014) [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Consolidated Tangible Net Worth, Actual	729,100,000
Consolidated Tangible Net Worth, Covenant	600,000,000
Adjusted Consolidated Leverage Ratio, Actual	2.74
Letter of Credit [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Line of Credit Facility, Maximum Borrowing Capacity	$ 100,000,000