CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income	$ 136,796	$ 54,630
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	46,677	44,693
Deferred income taxes	7,352	(4,592)
Write-off of deferred debt financing fees	12,733	0
Discount amortization on long-term debt	1,722	1,772
Loss on disposal of assets	4,785	6,577
Gain on sale of unconsolidated affiliate	(103,924)	0
Stock-based compensation	6,625	5,523
Equity in earnings from unconsolidated affiliates (in excess of) less than dividends received	(8,061)	(2,866)
Tax benefit related to stock-based compensation	(4,234)	(433)
Increase (decrease) in cash resulting from changes in:
Accounts receivable	28,508	20,786
Inventories	1,926	(46)
Prepaid expenses and other assets	8,940	729
Accounts payable	(2,577)	(3,426)
Accrued liabilities	5,756	11,777
Other liabilities and deferred credits	(10,548)	(226)
Net cash provided by operating activities	132,476	134,898
Cash flows from investing activities:
Capital expenditures	(339,559)	(113,405)
Proceeds from asset dispositions	155,603	96,376
Proceeds from sale of unconsolidated affiliate	112,210	0
Investment in unconsolidated affiliate	0	(7,153)
Net cash used in investing activities	(71,746)	(24,182)
Cash flows from financing activities:
Proceeds from borrowings	160,146	0
Debt issuance costs	(15,152)	0
Repayment of debt	(117,748)	(24,300)
Partial prepayment of put/call obligation	(27)	(33)
Common stock dividends paid	(18,138)	(14,297)
Issuance of common stock	11,550	7,869
Tax benefit related to stock-based compensation	4,234	433
Net cash provided by (used in) financing activities	24,865	(30,328)
Effect of exchange rate changes on cash and cash equivalents	12,303	6,411
Net increase (decrease) in cash and cash equivalents	97,898	86,799
Cash and cash equivalents at beginning of period	215,623	261,550
Cash and cash equivalents at end of period	313,521	348,349
Supplemental disclosure of cash flow information:
Interest	19,236	19,729
Income taxes	$ 16,092	$ 9,872