Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 537,726	$ 356,647
Accounts receivable:
Trade, net of allowance for uncollectible accounts of $2,984 and $1,778, respectively	50,904	101,825
Unbilled revenue and other	25,821	10,328
Current deferred tax assets	0	16,594
Other current assets	43,439	37,388
Total current assets	657,890	522,782
Property and equipment	2,511,931	2,450,890
Less accumulated depreciation	(824,096)	(799,280)
Property and equipment, net	1,687,835	1,651,610
Other assets, net	86,565	72,549
Total assets	2,432,290	2,246,941
Current liabilities:
Accounts payable	74,714	60,210
Accrued liabilities	58,020	58,614
Current maturities of long-term debt	67,724	67,571
Total current liabilities	200,458	186,395
Long-term debt	541,664	558,396
Deferred tax liabilities	148,187	167,351
Other non-current liabilities	49,942	52,985
Total liabilities	940,251	965,127
Commitments and contingencies
Shareholders’ equity:
Common stock, no par, 240,000 shares authorized, 147,646 and 120,630 shares issued, respectively	1,276,623	1,055,934
Retained earnings	306,439	322,854
Accumulated other comprehensive loss	(91,023)	(96,974)
Total shareholders’ equity	1,492,039	1,281,814
Total liabilities and shareholders’ equity	$ 2,432,290	$ 2,246,941