Condensed Consolidating Information - Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Condensed Consolidating Statements of Cash Flows
Net cash provided by operating activities	$ 288,899	$ 234,707
Net cash used in investing activities	(24,654)	(31,688)
Net cash provided by (used in) financing activities	(14,326)	(403,400)
Increase (decrease) in cash and equivalents	249,919	(200,381)
Cash and equivalents at beginning of period	727,032	361,363
Cash and equivalents at end of period	976,951	160,982
Reportable legal entity \| Parent
Condensed Consolidating Statements of Cash Flows
Net cash provided by operating activities	119,354	102,678
Net cash used in investing activities	(7,318)	(18,547)
Net cash provided by (used in) financing activities	138,777	(218,903)
Increase (decrease) in cash and equivalents	250,813	(134,772)
Cash and equivalents at beginning of period	636,877	265,313
Cash and equivalents at end of period	887,690	130,541
Reportable legal entity \| Guarantors
Condensed Consolidating Statements of Cash Flows
Net cash provided by operating activities	179,289	114,451
Net cash used in investing activities	(9,974)	(12,949)
Net cash provided by (used in) financing activities	(176,209)	(166,134)
Increase (decrease) in cash and equivalents	(6,894)	(64,632)
Cash and equivalents at beginning of period	81,976	81,690
Cash and equivalents at end of period	75,082	17,058
Reportable legal entity \| Combined Non-Guarantors
Condensed Consolidating Statements of Cash Flows
Net cash provided by operating activities	(6,917)	9,456
Net cash used in investing activities	(4,108)	(9,727)
Net cash provided by (used in) financing activities	17,025	(706)
Increase (decrease) in cash and equivalents	6,000	(977)
Cash and equivalents at beginning of period	8,179	14,360
Cash and equivalents at end of period	14,179	13,383
Consolidating Adjustments
Condensed Consolidating Statements of Cash Flows
Net cash provided by operating activities	(2,827)	8,122
Net cash used in investing activities	(3,254)	9,535
Net cash provided by (used in) financing activities	$ 6,081	$ (17,657)

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The increase (decrease) in cash associated with the entity's continuing operating, investing, and financing activities. While for technical reasons this element has no balance attribute, the default assumption is a debit balance consistent with its label.

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Amount of cash inflow (outflow) of investing activities, excluding discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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Amount of cash inflow (outflow) from operating activities, excluding discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

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