Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income	$ (2.2)	$ 8.6
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	79.5	71.0
Stock-based compensation expense, net of capitalized stock-based compensation expense	6.6	4.0
Amortization of aerial image library, deferred contract costs and lease incentive	3.0	4.2
Write-off of debt issuance costs and debt discount	0.5
Deferred income taxes	(2.4)	8.2
Amortization of debt issuance costs, accretion of debt discount, and other	1.1	0.8
Changes in working capital:
Accounts receivable, net	(6.9)	(10.9)
Deferred contract costs	(5.0)	(4.4)
Other current and non-current assets	(1.8)	(3.5)
Accounts payable	0.1	2.5
Accrued liabilities	(14.6)	(9.8)
Deferred revenue	(19.2)	(11.2)
Net cash flows provided by operating activities	38.7	59.5
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(20.9)	(38.6)
Investment in joint venture		(7.5)
Net cash flows used in investing activities	(20.9)	(46.1)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of debt and capital lease obligations	(38.3)	(1.9)
Repurchase of common stock		(60.9)
Value of shares surrendered to satisfy employee tax obligations	(6.8)	(1.8)
Proceeds from exercise of stock options and other	0.2	(0.9)
Net cash flows used in financing activities	(44.9)	(65.5)
Net decrease in cash, cash equivalents and restricted cash	(27.1)	(52.1)
Cash, cash equivalents and restricted cash, beginning of period	116.5	134.0
Cash, cash equivalents and restricted cash, end of period	89.4	81.9
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for interest, net of capitalized amounts of $5.1 and $16.6, respectively	8.7	5.9
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Changes to accruals for capital expenditures, including interest, and additions to capital lease obligations	(2.4)	6.8
Non-cash preferred stock dividend accrual	$ (1.0)	$ (1.0)