|
Acquisitions (Narrative) (Details) (USD $)
|
0 Months Ended | 6 Months Ended | |
|---|---|---|---|
|
Sep. 30, 2014
|
Jan. 31, 2015
|
Jul. 31, 2014
|
|
| Business Acquisition [Line Items] | |||
| Goodwill acquired | 218,319,000 | $ 166,406,000 | |
| Northern Technical [Member] | |||
| Business Acquisition [Line Items] | |||
| Percentage of voting interest acquired | 100.00% | ||
| Total consideration of transaction | 97,100,000 | ||
| Amount of intangible assets acquired | 6,200,000 | ||
| Net tangible assets | 32,200,000 | ||
| Goodwill acquired | $ 60,266,000 | ||
| Period from purchase date the purchase price allocation is expected to be finalized | 1 year | ||
| Northern Technical [Member] | Minimum [Member] | |||
| Business Acquisition [Line Items] | |||
| Estimated useful life, years | 6 months | ||
| Northern Technical [Member] | Maximum [Member] | |||
| Business Acquisition [Line Items] | |||
| Estimated useful life, years | 7 years |