Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 109.3	$ 126.1
Restricted cash	2.4	3.6
Accounts receivable, net of allowance for doubtful accounts of $1.6 and $2.8, respectively	114.6	90.8
Deferred contract costs	10.3	13.5
Prepaid and other current assets	23.8	17.4
Total current assets	260.4	251.4
Property and equipment, net of accumulated depreciation of $1,387.8 and $1,179.4, respectively (Note 4)	2,002.5	2,080.2
Goodwill (Note 5)	578.1	484.1
Intangible assets, net of accumulated amortization of $39.0 and $29.6, respectively	87.0	32.9
Long-term restricted cash	4.8	4.3
Long-term deferred contract costs	49.3	47.1
Other assets	27.8	13.2
Total assets	3,009.9	2,913.2
Current Liabilities:
Accounts payable	15.0	3.9
Current portion of long-term debt	47.2	5.5
Deferred revenue	86.3	80.3
Other accrued liabilities (Note 10)	70.7	64.4
Total current liabilities	219.2	154.1
Long-term debt, net of discount and debt issuance costs (Note 6)	1,242.1	1,104.4
Deferred revenue, non-current	216.9	284.0
Deferred income taxes, net, non-current (Note 11)	124.0	86.4
Other liabilities	34.8	36.2
Total liabilities	1,837.0	1,665.1
Stockholders' equity:
Series A convertible preferred stock, $0.001 par value; 0.08 shares authorized; 0.08 shares issued and outstanding at December 31, 2016 and 2015
Common stock; $0.001 par value; 250.0 shares authorized; 77.0 shares issued and 61.4 shares outstanding at December 31, 2016 and 76.6 shares issued and 67.4 shares outstanding at December 31, 2015	0.2	0.2
Treasury stock, at cost; 15.6 shares at December 31, 2016 and 9.2 shares at December 31, 2015	(342.0)	(225.8)
Additional paid-in capital	1,518.3	1,502.8
Accumulated deficit	(3.6)	(29.1)
Total stockholders' equity	1,172.9	1,248.1
Total liabilities and stockholders' equity	$ 3,009.9	$ 2,913.2