Short-Term Borrowing Short-Term Borrowing - Schedule of Short-Term Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 320,000
Long-term Line of Credit	168,757	$ 86,040
Short-term borrowing	173,397	88,231
Line of Credit Facility, Remaining Borrowing Capacity	151,243
Bank Overdrafts	4,640	2,191
Committed Line of Credit Facility One [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 55,000
Line of Credit Facility, Expiration Date	Oct. 31, 2016
Long-term Line of Credit	$ 30,000	20,000
Line of Credit Facility, Remaining Borrowing Capacity	25,000
Committed Line of Credit Facility Two [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 30,000
Line of Credit Facility, Expiration Date	Oct. 31, 2016
Long-term Line of Credit	$ 23,757	16,040
Line of Credit Facility, Remaining Borrowing Capacity	6,243
Committed Line of Credit Facility Three [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 35,000
Line of Credit Facility, Expiration Date	Dec. 20, 2016
Long-term Line of Credit	$ 30,000	0
Line of Credit Facility, Remaining Borrowing Capacity	5,000
Uncommitted Line Of Credit Facility One [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 150,000
Line of Credit Facility, Expiration Date	Oct. 08, 2020
Long-term Line of Credit	$ 35,000	0
Line of Credit Facility, Remaining Borrowing Capacity	115,000
Short-term Revolving Line of Credit Facility [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 50,000
Line of Credit Facility, Expiration Date	Oct. 31, 2016
Long-term Line of Credit	$ 50,000	$ 50,000
Line of Credit Facility, Remaining Borrowing Capacity	$ 0
Base Rate [Member] | Committed Line of Credit Facility Two [Member]
Short-term Debt [Line Items]
Debt Instrument, Basis Spread on Variable Rate	125.00%
Base Rate [Member] | Committed Line of Credit Facility Four [Member]
Short-term Debt [Line Items]
Debt Instrument, Basis Spread on Variable Rate	125.00%
Base Rate [Member] | Short-term Revolving Line of Credit Facility [Member]
Short-term Debt [Line Items]
Debt Instrument, Basis Spread on Variable Rate	80.00%