Short-Term Borrowing Short-Term Borrowing - Schedule of Short-Term Debt (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
Short-term Debt [Line Items]
Amount available under uncommitted credit facility	$ 62,446,000
Total short term credit facilities	165,000,000
Lines of credit outstanding amount	102,554,000		56,421,000
Bank Overdrafts	3,112,000	[1]	4,778,000	[1]
Short-term borrowing	105,666,000		61,199,000
Revolving credit facility
Short-term Debt [Line Items]
Total short term credit facilities	140,000,000
Lines of credit outstanding amount	40,000,000	[2]	10,000,000	[2]
Revolving credit facility | Committed Line of Credit Facility One
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	55,000,000
Amount available under uncommitted credit facility	20,000,000
Lines of credit outstanding amount	35,000,000		30,000,000
Revolving credit facility | Uncommitted line of credit first facility
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	20,000,000
Amount available under uncommitted credit facility	20,000,000
Lines of credit outstanding amount	0		0
Revolving credit facility | Committed Line of Credit Facility Two
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	30,000,000
Amount available under uncommitted credit facility	12,446,000	[3]
Lines of credit outstanding amount	17,554,000	[3]	16,421,000	[3]
Revolving credit facility | Uncommitted line of credit second facility
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	20,000,000	[4]
Amount available under uncommitted credit facility	10,000,000	[4]
Lines of credit outstanding amount	$ 10,000,000	[4]	$ 0	[4]

[1] If presented, these book overdrafts would be funded through the bank revolving credit facilities.

[2] At our discretion, the borrowings under this facility can bear interest at the lender's base rate plus 0.80 percent.

[3] This facility bears interest at LIBOR for the applicable period plus 1.25 percent, if requested three days prior to the advance date. If requested and advanced on the same day, this facility bears interest at a base rate plus 1.25 percent.

[4] We have issued $4.7 million in letters of credit under this credit facility as of December 31, 2013. There have been no draws on these letters of credit and we do not anticipate that they will be drawn upon by the counter-parties. We expect that the letters of credit will be renewed to the extent necessary in the future.