Derivative Instruments (Details)	5 Months Ended	12 Months Ended					12 Months Ended											12 Months Ended							12 Months Ended
	May 22, 2013 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Jul. 02, 2013 USD ($)	Aug. 30, 2012 Number	Dec. 31, 2013 Interest Rate Swap [Member] USD ($)	Dec. 31, 2012 Interest Rate Swap [Member] USD ($)	Dec. 31, 2011 Interest Rate Swap [Member] USD ($)	Dec. 31, 2013 Foreign Exchange Contract [Member] USD ($)	Dec. 31, 2012 Foreign Exchange Contract [Member] USD ($)	Dec. 31, 2011 Foreign Exchange Contract [Member] USD ($)	Sep. 17, 2012 Foreign Exchange Contract [Member] CAD	Sep. 17, 2012 Foreign Exchange Contract [Member] GBP (£)	Aug. 30, 2012 Foreign Exchange Contract [Member] GBP (£)	May 03, 2012 Foreign Exchange Contract [Member] CAD	Feb. 15, 2012 Foreign Exchange Contract [Member] CAD	Dec. 31, 2012 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] USD ($)	Dec. 31, 2011 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] USD ($)	Dec. 01, 2013 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] CAD	Nov. 01, 2013 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] GBP (£)	Jul. 12, 2013 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] GBP (£)	Apr. 04, 2013 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] CAD	Jan. 15, 2013 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] GBP (£)	Dec. 31, 2013 Realized Loss [Member] Interest Rate Swap [Member] USD ($)	Dec. 31, 2012 Realized Loss [Member] Interest Rate Swap [Member] USD ($)	Dec. 31, 2011 Realized Loss [Member] Interest Rate Swap [Member] USD ($)	Dec. 31, 2013 Realized Loss [Member] Foreign Exchange Contract [Member] USD ($)	Dec. 31, 2013 Interest Expense [Member] Interest Rate Swap [Member] USD ($)	Dec. 31, 2012 Interest Expense [Member] Interest Rate Swap [Member] USD ($)	Dec. 31, 2011 Interest Expense [Member] Interest Rate Swap [Member] USD ($)
Impact of derivative instruments on the statement of operations and OCI
Gain (loss) on interest rate swap recognized in OCI (effective portion)							$ (16,000)	$ 3,200,000	$ 3,189,000
Gain (loss) on interest rate swaps reclassified from AOCI into income (effective portion)																													(1,914,000)	(1,596,000)	1,781,000
Gain (loss) on interest rate swaps recognized in income																									0	(96,000)	0
Gain (loss) on forward exchange contracts recognized										(28,244,000)	(5,134,000)	0																(4,470,000)
Derivative Instruments (Textuals) [Abstract]
Notional amount of swap					144,411,000								14,000,000	23,000,000	125,000,000	250,000,000	250,000,000			600,000,000	225,000,000	675,000,000	600,000,000	675,000,000
Number of interest rate swaps						2
Loss (gain) on derivatives, net	$ 10,355,000	$ (4,470,000)	$ 1,825,000	$ 0														$ 1,921,000	$ 0