Restructuring and Related Charges and Impairment Loss (Details) (USD $)	3 Months Ended		12 Months Ended
	Dec. 31, 2011		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Restructuring Cost and Reserve [Line Items]
Cumulative net cash and non-cash charges			$ 1,800,000
Restructuring Reserve [Roll Forward]
Accrued restructuring and related charges, beginning of period			10,009,000		7,607,000		0
Additions			1,773,000		8,430,000		8,507,000
Payments			(8,190,000)		(5,128,000)		(900,000)
Adjustments			(636,000)		(900,000)		0
Accrued restructuring and related charges, end of period	10,009,000		2,956,000		10,009,000		7,607,000
Non-cash charges primarily consisting of share-based compensation costs			600,000
Impairment loss	183,300,000		0		183,288,000		0
Goodwill impairment Loss					182,400,000
Intangible asset write-off					900,000
2011 Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Accrued restructuring and related charges, beginning of period			8,426,000	[1]	0	[1]	0	[1]
Additions			0	[1]	8,430,000	[1]	0	[1]
Payments			(7,368,000)	[1]	(4,000)	[1]	0	[1]
Adjustments			(504,000)	[1],[2]	0	[1]	0	[1]
Accrued restructuring and related charges, end of period	8,426,000	[1]	554,000	[1]	8,426,000	[1]	0	[1]
2010 Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Accrued restructuring and related charges, beginning of period			1,583,000	[3]	7,607,000	[3]	0	[3]
Additions			0	[3]	0	[3]	8,507,000	[3]
Payments			(822,000)	[3]	(5,124,000)	[3]	(900,000)	[3]
Adjustments			(132,000)	[4]	(900,000)	[3],[4]	0	[3]
Accrued restructuring and related charges, end of period	1,583,000	[3]	629,000	[3]	1,583,000	[3]	7,607,000	[3]
Non-cash charges primarily consisting of share-based compensation costs			1,800,000
2012 Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Accrued restructuring and related charges, beginning of period			0		0		0
Additions			1,773,000		0		0
Payments			0		0		0
Adjustments			0		0		0
Accrued restructuring and related charges, end of period	$ 0		$ 1,773,000		$ 0		$ 0

[1] Excludes non-cash charges of approximately $0.6 million, which primarily consisted of share-based compensation costs.

[2] Adjustments resulted primarily from actual employee tax and benefit amounts differing from previous estimates.

[3] Excludes non-cash charges of approximately $1.8 million, which primarily consisted of share-based compensation costs.

[4] Adjustments resulted primarily from a favorable adjustment to lease termination costs due to a sublease of certain unused office space.