Fair Value of Financial Assets (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	$ 8,301	$ 24,467
Fair Value, Inputs, Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	16	4,588
Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	8,285	19,879
Money Market Funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	16	4,588
Money Market Funds | Fair Value, Inputs, Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	16	4,588
Time deposits
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value		6,540
Time deposits | Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value		6,540
Corporate Bonds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	4,571	6,706
Corporate Bonds | Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	4,571	6,706
U.S. Federal Agencies
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value
U.S. Federal Agencies | Fair Value, Inputs, Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value
U.S. Federal Agencies | Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value
U.S. Federal Agencies | Fair Value, Inputs, Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value
Foreign Bonds and Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	2,014	4,832
Foreign Bonds and Notes | Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	2,014	4,832
Variable Rate Demand Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	1,700	1,801
Variable Rate Demand Notes | Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	1,700	1,801
Mutual Funds Held in Rabbi Trust
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	484	442
Mutual Funds Held in Rabbi Trust | Fair Value, Inputs, Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	$ 484	$ 442