|
Changes in Carrying Amount of Goodwill (Detail) (USD $)
In Thousands, unless otherwise specified |
12 Months Ended | 12 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|---|
|
Dec. 31, 2013
|
Dec. 31, 2011
|
Dec. 31, 2013
Power Fuels Merger
|
Dec. 31, 2012
Power Fuels Merger
|
Nov. 30, 2012
Power Fuels Merger
|
Dec. 31, 2012
Other acquisitions
|
|
| Goodwill [Line Items] | ||||||
| Beginning Balance | $ 415,176 | $ 90,008 | $ 304,031 | |||
| Additions | 341 | 312,715 | 12,453 | |||
| Acquisition adjustments, net | (6,821) | (8,700) | ||||
| Ending Balance | $ 408,696 | $ 90,008 | $ 304,031 | |||