Fair Value Measurements - Summary of Fair Value Assets Measured on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands		Sep. 30, 2018	Dec. 31, 2017
Fair value information related to assets
Assets		$ 3,020	$ 2,756
Quoted Prices in Active Markets (Level 1)
Fair value information related to assets
Assets		3,020	2,756
Money market funds
Fair value information related to assets
Assets	[1]	120	119
Money market funds | Quoted Prices in Active Markets (Level 1)
Fair value information related to assets
Assets	[1]	120	119
Other mutual funds
Fair value information related to assets
Assets	[2]	2,900	2,637
Other mutual funds | Quoted Prices in Active Markets (Level 1)
Fair value information related to assets
Assets	[2]	$ 2,900	$ 2,637

[1] Money market funds are included in “Cash and cash equivalents” in the Condensed Consolidated Balance Sheets. These investments are classified as available-for-sale and are recorded at fair value. There have been no realized gains or losses related to these investments and we have not experienced any redemption restrictions with respect to any of the money market mutual funds.

[2] Other mutual funds are included in “Other investments and assets” in the Condensed Consolidated Balance Sheets. Upon the adoption of ASU 2016-01, unrealized gains on equity securities that were previously classified as available-for-sale are recognized in net income rather than “Accumulated other comprehensive income (loss)” (“AOCI”). We adopted this guidance prospectively on January 1, 2018 and recognized a cumulative-effect adjustment of $0.6 million to beginning retained earnings, which represents unrealized gains of $1.0 million ($0.6 million after tax) as of December 31, 2017 that were included in AOCI in the Condensed Consolidated Balance Sheets. Refer to Note 14 – Stockholders’ Equity for additional information.