Supplemental Cash Flow Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Supplemental disclosure of cash flow information:
Interest paid	$ 0.1us-gaap_InterestPaid	$ 0.4us-gaap_InterestPaid
Income taxes paid	1.0us-gaap_IncomeTaxesPaid	0.7us-gaap_IncomeTaxesPaid
Non-cash investing and financing activities:
Stock repurchases not yet settled (accrued in accounts payable)	1.8	0
Unpaid purchases of property and equipment	$ 1.3	$ 3.4

Future cash outflow to pay for purchases of fixed assets that have occurred.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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The amount of cash paid for interest during the period.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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The value of the noncash (or part noncash) consideration given (for example, liability, equity) in a transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of a transaction not resulting in cash receipts or cash payments in the period.

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