Fair Value Measurements - Recurring and Nonrecurring Basis (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended									12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Fair value information related to assets
Goodwill impairment charge	$ 0		$ (5,413)	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ (5,413)		$ 0	$ 0
Money market funds
Fair value information related to assets
Assets	118					10,177				118		10,177
Other mutual funds
Fair value information related to assets
Assets	2,023					1,239				2,023		1,239
Fair Value, Measurements, Recurring
Fair value information related to assets
Assets	2,141					11,416				2,141		11,416
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1)
Fair value information related to assets
Assets	2,141					11,416				2,141		11,416
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1) | Money market funds
Fair value information related to assets
Assets	118					10,177				118		10,177
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1) | Other mutual funds
Fair value information related to assets
Assets	2,023					1,239				2,023		1,239
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair value information related to assets
Assets	0					0				0		0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Money market funds
Fair value information related to assets
Assets	0					0				0		0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Other mutual funds
Fair value information related to assets
Assets	0					0				0		0
Fair Value, Measurements, Recurring | Significant Unobserved Inputs (Level 3)
Fair value information related to assets
Assets	0					0				0		0
Fair Value, Measurements, Recurring | Significant Unobserved Inputs (Level 3) | Money market funds
Fair value information related to assets
Assets	0					0				0		0
Fair Value, Measurements, Recurring | Significant Unobserved Inputs (Level 3) | Other mutual funds
Fair value information related to assets
Assets	0					0				0		0
Fair Value, Measurements, Nonrecurring
Fair value information related to assets
Goodwill, Fair Value Disclosure	0									0
Property, Plant, and Equipment, Fair Value Disclosure	0	[1]								0	[1]
Assets	0									0
Goodwill impairment charge										(5,413)
Fair Value, Measurements, Nonrecurring | Goodwill (1)
Fair value information related to assets
Goodwill impairment charge										(4,461)
Fair Value, Measurements, Nonrecurring | Property and equipment(1)
Fair value information related to assets
Goodwill impairment charge										(952)	[1]
Fair Value, Measurements, Nonrecurring | Quoted Prices in Active Markets (Level 1)
Fair value information related to assets
Goodwill, Fair Value Disclosure	0									0
Property, Plant, and Equipment, Fair Value Disclosure	0	[1]								0	[1]
Assets	0									0
Fair Value, Measurements, Nonrecurring | Significant Other Observable Inputs (Level 2)
Fair value information related to assets
Goodwill, Fair Value Disclosure	0									0
Property, Plant, and Equipment, Fair Value Disclosure	0	[1]								0	[1]
Assets	0									0
Fair Value, Measurements, Nonrecurring | Significant Unobserved Inputs (Level 3)
Fair value information related to assets
Goodwill, Fair Value Disclosure	0									0
Property, Plant, and Equipment, Fair Value Disclosure	0	[1]								0	[1]
Assets	$ 0									$ 0

[1] See Notes 5 and 7 for details of the impairment charges.