Derivative Financial Instruments Derivative Financial Instruments Narrative (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) contracts	Dec. 31, 2014 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (200,607,000)	$ (135,060,000)	$ (193,920,000)	$ (180,616,000)	$ (194,989,000)	$ (80,636,000)	$ (32,245,000)	$ (24,258,000)
Long-term Debt	$ 371,212,000
Forward Contracts [Member]
Derivative [Line Items]
Description of Derivative Activity Volume	516
Secured Debt [Member]
Derivative [Line Items]
Long-term Debt	$ 371,212,000	323,969,000
Interest Rate Swap [Member] | 2011 Credit Facility USD Term Loan Interest Rate Swaps [Member]
Derivative [Line Items]
Number of Interest Rate Derivatives Held | contracts	6
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ 500,000
Derivative, Notional Amount	$ 200,000,000
Derivative, Fixed Interest Rate	1.00%
Interest Rate Swap [Member] | 2015 Credit Facility USD Term Loan Interest Rate Swaps [Member] [Member]
Derivative [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ 300,000
Derivative, Notional Amount	$ 214,000,000
Derivative, Fixed Interest Rate	1.42%
Interest Rate Cap [Member] | 2015 Credit Facility USD Term Loan Interest Rate Swaps [Member] [Member]
Derivative [Line Items]
Derivative, Cap Interest Rate	2.00%
Derivative, Notional Amount	$ 100,000,000
Derivative Purchase Price	1,700,000
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Minimum [Member]
Derivative [Line Items]
Derivative, Notional Amount	118,000
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Maximum [Member]
Derivative [Line Items]
Derivative, Notional Amount	23,400,000
Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Nonderivative Instruments [Member]
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (14,380,000)	$ (14,380,000)							$ (14,380,000)	$ (14,380,000)
Number of Counterparties [Member]
Derivative [Line Items]
Description of Derivative Activity Volume	nine	eight
London Interbank Offered Rate (LIBOR) [Member] | Secured Debt [Member]
Derivative [Line Items]
Long-term Debt	$ 314,400,000