Taxes (Details 1) - Provision for Income Taxes and Tax Rate Reconciliation (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current:
Federal	$ 35,912,000	$ 38,720,000	$ 18,372,000
Foreign	12,071,000	19,248,000	14,976,000
State	4,121,000	4,296,000	4,011,000
Total current	52,104,000	62,264,000	37,359,000
Deferred:
Federal	(3,886,000)	1,359,000	4,345,000
Foreign	(1,621,000)	(910,000)	(877,000)
State	(2,575,000)	(124,000)	(809,000)
Total deferred	(8,082,000)	325,000	2,659,000
Total provision for income taxes	44,022,000	62,589,000	40,018,000
Income Before Income Taxes
Income from foreign operations included in income before income taxes	$ 39,700,000	$ 61,600,000	$ 51,700,000
Reconciliation of Statutory Federal Tax Rate to Effective Tax Rate
Statutory federal tax rate	35.00%	35.00%	35.00%
State taxes, net of federal benefit	0.70%	1.50%	1.90%
Tax rate differentials for international jurisdictions	(3.80%)	(2.00%)	(4.10%)
Permanent differences	1.30%	2.50%	1.80%
Other, net	0.50%	0.30%	(0.20%)
Effective tax rate	33.70%	37.30%	34.40%