Long-Term Debt and Commitments (Details)	12 Months Ended						12 Months Ended			12 Months Ended			12 Months Ended			12 Months Ended		12 Months Ended		12 Months Ended				12 Months Ended
	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2013 Series 2006 A Senior Notes Due 2013 [Member] USD ($)	Dec. 31, 2012 Series 2006 A Senior Notes Due 2013 [Member] USD ($)	Oct. 05, 2006 Series 2006 A Senior Notes Due 2013 [Member] USD ($)	Dec. 31, 2013 Floating Rate Series 2006 A Senior Notes Due 2013 [Member] USD ($)	Dec. 31, 2012 Floating Rate Series 2006 A Senior Notes Due 2013 [Member] USD ($)	Oct. 05, 2006 Floating Rate Series 2006 A Senior Notes Due 2013 [Member] USD ($)	Dec. 31, 2013 Series A Senior Notes Due 2020 [Member] USD ($)	Oct. 07, 2013 Series A Senior Notes Due 2020 [Member] USD ($)	Dec. 31, 2012 Series A Senior Notes Due 2020 [Member] USD ($)	Dec. 31, 2013 Series B Senior Notes Due 2023 [Member] USD ($)	Oct. 07, 2013 Series B Senior Notes Due 2023 [Member] USD ($)	Dec. 31, 2012 Series B Senior Notes Due 2023 [Member] USD ($)	Dec. 31, 2013 Variable/Fixed Rate Industrial Development Revenue Bonds Series 1999 Due 2014 [Member] USD ($)	Dec. 31, 2012 Variable/Fixed Rate Industrial Development Revenue Bonds Series 1999 Due 2014 [Member] USD ($)	Dec. 31, 2013 Installment Obligations [Member] USD ($)	Dec. 31, 2012 Installment Obligations [Member] USD ($)	Dec. 31, 2013 Other Borrowings [Member] USD ($)	Dec. 31, 2012 Other Borrowings [Member] USD ($)	Jan. 31, 2011 Other Borrowings [Member] USD ($)	Jan. 31, 2011 Other Borrowings [Member] CNY	Dec. 31, 2013 Note Purchase Agreement [Member] USD ($)	Oct. 07, 2013 Note Purchase Agreement [Member] USD ($)	Oct. 05, 2006 Note Purchase Agreement [Member] USD ($)
Debt Instrument [Line Items]
Long-term debt, gross	$ 83,200,000	$ 85,500,000		$ 0	$ 50,000,000	$ 50,000,000	$ 0	$ 25,000,000	$ 25,000,000	$ 30,000,000	$ 30,000,000	$ 0	$ 45,000,000	$ 45,000,000	$ 0	$ 8,200,000	$ 8,200,000	$ 0	$ 1,400,000	$ 0	$ 900,000	$ 10,600,000	1,600,000		$ 75,000,000	$ 75,000,000
Less: Current maturities	8,200,000	76,977,000
Long-term debt	75,000,000	8,478,000
Interest rate on debt instrument (in hundredths)				5.53%						3.46%			4.13%
Maturity date				Oct. 05, 2013			Oct. 05, 2013			Oct. 07, 2020			Oct. 07, 2023			Nov. 01, 2014		Dec. 31, 2013		Dec. 31, 2014
Term of debt instrument (in years)																15 years		3 years
Average interest rates (in hundredths)							0.73%	0.92%		3.46%			4.13%			0.13%	0.22%	4.25%		6.80%
Cost of land and limestone ore reserves acquired																		17,500,000
Cash paid on closing of land and limestone ore reserves acquisition																		6,100,000
Principal amount of debt at issuance																		11,400,000
Repayments of long-term debt	77,277,000	8,558,000	275,000																					75,000,000
Long-term debt maturities [Abstract]
2014	8,200,000
2015	0
2016	0
2017	0
2018	0
Thereafter	75,000,000
Short-term Borrowings [Abstract]
Uncommitted short-term bank credit lines, maximum borrowing capacity	189,700,000
Uncommitted short-term bank credit lines, amount outstanding	5,500,000
Short-term debt	5,504,000	7,111,000
Weighted average interest rate on short-term borrowings (in hundredths)	4.80%	5.80%
Interest costs [Abstract]
Interest costs	3,400,000	3,500,000	3,500,000
Capitalized interest cost	$ 100,000	$ 300,000	$ 300,000