Fair Value of Financial Instruments Credit Facilities (Details)			1 Months Ended									3 Months Ended
	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Mar. 31, 2013 Amendment Agreement [Member]	Mar. 31, 2014 Revolving credit facility [Member] USD ($)	Dec. 31, 2013 Revolving credit facility [Member] USD ($)	Mar. 31, 2014 United States revolver [Member] USD ($)	Mar. 31, 2014 European revolver [Member] [Member] USD ($)	Mar. 31, 2014 European revolver [Member] [Member] EUR (€)	Mar. 31, 2014 Australian term loan [Member] USD ($)	Mar. 31, 2014 Australian term loan [Member] AUD	Dec. 31, 2013 Australian term loan [Member] USD ($)	Mar. 31, 2014 Australian term loan [Member] Prepayment [Member] USD ($)	Mar. 31, 2014 Australian term loan [Member] Prepayment [Member] AUD	Mar. 31, 2014 United States term loan [Member] USD ($)	Dec. 31, 2013 United States term loan [Member] USD ($)
Reduction in applicable margins			0.25%
Total revolving credit facility				$ 425,000,000
Revolving credit facility, amount outstanding				16,300,000		11,000,000	5,300,000	3,900,000
Letters of credit guarantees				3,200,000
Unused borrowing capacity				405,500,000
Stated interest rate						1.90%	1.97%	1.97%	4.44%	4.44%				1.90%
Prepayments of debt												30,500,000	34,000,000
Outstanding term loans	$ 1,579,559,000	$ 1,624,712,000		$ 16,302,000	$ 15,949,000				$ 106,401,000	114,800,000	$ 134,436,000			$ 1,418,579,000	$ 1,433,414,000