Fair Value of Stock Settled Performance Units (Detail) (USD $)
In Thousands, unless otherwise specified |
12 Months Ended |
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Dec. 31, 2013
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Performance Unit Awards 2013
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Schedule of Share based Compensation Arrangements by Share based Payment Award, Performance Options [Line Items] | |
Aggregate fair value at date of grant | $ 5,564 |
Performance Unit Awards 2012
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Schedule of Share based Compensation Arrangements by Share based Payment Award, Performance Options [Line Items] | |
Aggregate fair value at date of grant | 3,065 |
Performance Unit Awards 2011
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Schedule of Share based Compensation Arrangements by Share based Payment Award, Performance Options [Line Items] | |
Aggregate fair value at date of grant | 5,569 |
Performance Unit Awards 2010
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Schedule of Share based Compensation Arrangements by Share based Payment Award, Performance Options [Line Items] | |
Aggregate fair value at date of grant | $ 3,117 |