Long-Term Debt (Details) (USD $)	0 Months Ended																	0 Months Ended			0 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	May 16, 2013 Term A Loans, Term B Loans and Revolving Loans [Member]	Sep. 30, 2013 Notes Payable to Banks [Member] Term-B Loan Facility due May 2020 [Member]	May 16, 2013 Notes Payable to Banks [Member] Term-B Loan Facility due May 2020 [Member]	Sep. 30, 2013 Notes Payable to Banks [Member] Term-A Loan Facility due May 2017 [Member]	Dec. 31, 2012 Notes Payable to Banks [Member] Term-A Loan Facility due May 2017 [Member]	Sep. 30, 2013 Notes Payable to Banks [Member] Term-B Loan Facility due May 2019 [Member]	Dec. 31, 2012 Notes Payable to Banks [Member] Term-B Loan Facility due May 2019 [Member]	May 16, 2013 Notes Payable to Banks [Member] Senior Secured Credit Agreement [Member]	Sep. 30, 2013 Notes Payable to Banks [Member] Term-A Loan Facility due May 2018 [Member]	May 16, 2013 Notes Payable to Banks [Member] Term-A Loan Facility due May 2018 [Member]	Sep. 30, 2013 Revolving Credit Facility [Member]	Sep. 30, 2013 Revolving Credit Facility [Member] Revolving Credit Facility due May 2017 [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Revolving Credit Facility due May 2017 [Member]	May 16, 2013 Revolving Credit Facility [Member] Revolving Credit Facility due May 2018 [Member]	May 16, 2013 Eurodollar [Member] Notes Payable to Banks [Member] Term-B Loan Facility due May 2020 [Member]	Sep. 30, 2013 Maximum [Member]	May 16, 2013 Maximum [Member] Revolving Credit Facility [Member] Revolving Credit Facility due May 2018 [Member]	May 16, 2013 Maximum [Member] Eurodollar [Member] Notes Payable to Banks [Member] Revolving Loans and Term A Loans [Member]	May 16, 2013 Minimum [Member] Revolving Credit Facility [Member] Revolving Credit Facility due May 2018 [Member]	May 16, 2013 Minimum [Member] Eurodollar [Member] Notes Payable to Banks [Member] Revolving Loans and Term A Loans [Member]	May 16, 2013 Minimum [Member] Eurodollar [Member] Notes Payable to Banks [Member] Term-B Loan Facility due May 2020 [Member]
Debt Disclosure [Abstract]
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year	$ 2,500,000
Long-term Debt, Maturities, Repayments of Principal in Year Two	10,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Three	10,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Four	10,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Five	10,875,000
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	314,438,000
Long-term Debt	357,813,000
Debt Instrument [Line Items]
Line of Credit Facility, Increase in Additional Principal Amount										100,000,000
Leverage Ratio in Latest Year of Debt Term																		3.25
Debt Instrument, Basis Spread on Variable Rate																	2.50%			2.50%		1.75%	1.00%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage																			0.40%		0.25%
Debt Instrument, Face Amount					275,000,000							100,000,000
Senior Secured Debt	357,813,000	426,588,000		262,813,000		0	92,500,000	0	334,088,000		95,000,000			0	0
Line of Credit Facility, Maximum Borrowing Capacity			500,000,000													125,000,000
Line of Credit Facility, Remaining Borrowing Capacity													$ 122,500,000
Debt Instrument, Interest Rate at Period End				3.50%							2.20%
Leverage Ratio	2.16																	4.25
Debt, Weighted Average Interest Rate	3.20%
Pledged equity interest in foreign subsidiaries	65.00%