Fair Value Measurements - Recurring and Nonrecurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair value information related to assets
Assets	$ 9,691	$ 11,054
Liabilities	(1,114)	(1,210)
Earnout contingent consideration liability
Fair value information related to assets
Liabilities	(1,114)	(1,210)
Quoted Prices in Active Markets (Level 1)
Fair value information related to assets
Assets	9,691	11,054
Liabilities	0	0
Quoted Prices in Active Markets (Level 1) | Earnout contingent consideration liability
Fair value information related to assets
Liabilities	0	0
Significant Other Observable Inputs (Level 2)
Fair value information related to assets
Assets	0	0
Liabilities	0	0
Significant Other Observable Inputs (Level 2) | Earnout contingent consideration liability
Fair value information related to assets
Liabilities	0	0
Significant Unobserved Inputs (Level 3)
Fair value information related to assets
Assets	0	0
Liabilities	(1,114)	(1,210)
Significant Unobserved Inputs (Level 3) | Earnout contingent consideration liability
Fair value information related to assets
Liabilities	(1,114)	(1,210)
Money market funds
Fair value information related to assets
Assets	7,320	8,518
Money market funds | Quoted Prices in Active Markets (Level 1)
Fair value information related to assets
Assets	7,320	8,518
Money market funds | Significant Other Observable Inputs (Level 2)
Fair value information related to assets
Assets	0	0
Money market funds | Significant Unobserved Inputs (Level 3)
Fair value information related to assets
Assets	0	0
Other mutual funds
Fair value information related to assets
Assets	2,371	2,536
Other mutual funds | Quoted Prices in Active Markets (Level 1)
Fair value information related to assets
Assets	2,371	2,536
Other mutual funds | Significant Other Observable Inputs (Level 2)
Fair value information related to assets
Assets	0	0
Other mutual funds | Significant Unobserved Inputs (Level 3)
Fair value information related to assets
Assets	$ 0	$ 0