Financial Instruments (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
3.24% $100 Million Interest Rate Swap [Member] | Designated as a Cash Flow Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Line Of Credit Facility Forecasted Borrowing Amount	$ 100,000,000		$ 100,000,000
Derivative, Fixed Interest Rate	3.24%		3.24%
Interest Rate Derivative Liabilities, at Fair Value	4,000,000		4,000,000		5,300,000
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)	(100,000)	200,000	(200,000)	200,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(100,000)	100,000	(100,000)	100,000
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(778,000)	(766,000)	(1,546,000)	(1,522,000)
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net, Net of Tax	(500,000)	(500,000)	(1,000,000)	(900,000)
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	(3,100,000)		(3,100,000)
Interest Rate Cash Flow Hedge Gain Loss To Be Reclassified During Next 12 Months Net of Tax	(1,900,000)		(1,900,000)
Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness	0		0
2.52% $50 Million Interest Rate Swap [Member] | Designated as a Cash Flow Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Line Of Credit Facility Forecasted Borrowing Amount	50,000,000		50,000,000
Derivative, Fixed Interest Rate	2.52%		2.52%
Interest Rate Derivative Assets, at Fair Value		1,300,000		1,300,000
Interest Rate Derivative Liabilities, at Fair Value	400,000		400,000
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)	(900,000)	900,000	(1,600,000)	900,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(600,000)	600,000	(1,000,000)	600,000
Foreign Exchange Forward [Member] | Designated as a Cash Flow Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	77,400,000		77,400,000		78,200,000
Foreign Currency Cash Flow Hedge Asset at Fair Value	400,000		400,000		300,000
Foreign Currency Cash Flow Hedge Liability at Fair Value					100,000
Unrealized Gain (Loss) on Foreign Currency Derivatives, Net, before Tax	100,000	(500,000)	400,000	(1,300,000)
Unrealized Gain (Loss) on Foreign Currency Derivatives, Net, After Tax	42,000	(400,000)	300,000	(1,100,000)
Foreign Currency Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	164,000	(557,000)	205,000	(1,031,000)
Foreign Currency Cash Flow Hedge Gain Loss Reclassified To Earnings, Net, After Tax	131,000	(400,000)	200,000	(800,000)
Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months	400,000		400,000
Foreign Currency Cash Flow Hedge Gain Loss To Be Reclassified During Next 12 Months Net of Tax	300,000		300,000
Gain (Loss) on Foreign Currency Cash Flow Hedge Ineffectiveness	0		0
Foreign Exchange Forward [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	189,200,000		189,200,000		180,300,000
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	300,000		300,000		700,000
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	400,000		400,000		400,000
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	$ (700,000)	$ 1,500,000	$ (900,000)	$ (700,000)