Acquisitions - Pro Forma Condensed Consolidated Income Statement (Detail) - USD ($) $ / shares in Units, $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Business Acquisition Pro Forma Information [Abstract] | ||
| Net service revenue | $ 1,327.3 | $ 1,247.6 |
| Operating (loss) income | (7.9) | 21.0 |
| Net (loss) income | $ 0.2 | $ 10.9 |
| Basic (loss) earnings per share | $ 0.01 | $ 0.34 |
| Diluted (loss) earnings per share | $ 0.01 | $ 0.33 |