Goodwill (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 2012	Sep. 30, 2011
Goodwill [Line Items]
Highest goodwill balance among other reporting units				$ 5,700,000
Average goodwill balance among other reporting units				800,000
Total goodwill balance - Impaired Reporting Units					4,600,000
Number of reporting units with allocated goodwill balances				209
Goodwill Carrying Value - UK Reporting Unit				6,900,000
Goodwill, impairment	6,946,000	1,550,000	0
Goodwill [Roll Forward]
Balance, beginning of period	179,423,000	179,286,000
Acquired goodwill	0	137,000
Goodwill, Translation Adjustments	(174,000)
Balance, end of period	179,249,000	179,423,000	179,286,000
Accumulated goodwill impairment losses	(2,320,000)	(770,000)
Goodwill impairment	(6,946,000)	(1,550,000)	0
Accumulated goodwill impairment losses	(9,266,000)	(2,320,000)	(770,000)
Goodwill	$ 169,983,000	$ 177,103,000