Fair Value Measurements (Details) (USD $)	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Liabilities [Abstract]
Cash and cash equivalents	$ 1,759,000		$ 864,000		$ 1,064,000	$ 2,356,000
Outstanding borrowings under the Fifth Amended Credit Agreement	286,900,000
Outstanding borrowings under the Fifth Amended Credit Agreement	287,575,000
Recurring [Member] | Foreign Exchange Contract [Member] | Level 2 [Member]
Assets [Abstract]
Assets, Fair Value	73,000		315,000
Liabilities [Abstract]
Liabilities, Fair Value	255,000		321,000
Recurring [Member] | Foreign Exchange Contract [Member] | Gross Fair Value [Member]
Assets [Abstract]
Assets, Fair Value	73,000		315,000
Liabilities [Abstract]
Liabilities, Fair Value	255,000		321,000
Recurring [Member] | Foreign Exchange Contract [Member] | Netting [Member]
Assets [Abstract]
Assets, Fair Value	(73,000)	[1]	(212,000)	[1]
Liabilities [Abstract]
Liabilities, Fair Value	(73,000)	[1]	(212,000)	[1]
Recurring [Member] | Foreign Exchange Contract [Member] | Net Fair Value [Member]
Assets [Abstract]
Assets, Fair Value	0		103,000
Liabilities [Abstract]
Liabilities, Fair Value	182,000		109,000
Recurring [Member] | Interest Rate Swap [Member] | Level 2 [Member]
Liabilities [Abstract]
Liabilities, Fair Value	2,963,000		4,235,000
Recurring [Member] | Interest Rate Swap [Member] | Gross Fair Value [Member]
Liabilities [Abstract]
Liabilities, Fair Value	2,963,000		4,235,000
Recurring [Member] | Interest Rate Swap [Member] | Netting [Member]
Liabilities [Abstract]
Liabilities, Fair Value	0	[1]	0	[1]
Recurring [Member] | Interest Rate Swap [Member] | Net Fair Value [Member]
Liabilities [Abstract]
Liabilities, Fair Value	$ 2,963,000		$ 4,235,000

[1] This column reflects the impact of netting derivative assets and liabilities by counterparty when a legally enforceable master netting agreement exists.