Stock-Based Employee Compensation - Stock Granted to Our Non-employee Directors (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	6 Months Ended	1 Months Ended
Jun. 30, 2013	Jun. 30, 2013	Jan. 31, 2013 Director [Member]	Feb. 29, 2012 Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares	0	0	29,205	31,820
Fair Value per Share			$ 7.55	$ 6.60
Fair Value of Grant			$ 221	$ 210

Gross number of share options (or share units) granted during the period.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration