Subsidiary Guarantors Consolidated Cash Flow (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	$ 299,125	$ 134,086	$ 208,535
Net cash provided by (used in) investing activities	(824,003)	(405,640)	(425,154)
Net cash provided by (used in) financing activities	408,499	467,706	224,944
Decrease in cash	(116,379)	196,152	8,325
Cash at beginning of year	212,884	16,732	8,407
Cash at end of year	96,505	212,884	16,732
Consolidation, Eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	0	0	0
Net cash provided by (used in) investing activities	(106,595)	384,801	563,505
Net cash provided by (used in) financing activities	106,595	(384,801)	(563,505)
Decrease in cash	0	0	0
Cash at beginning of year	0	0	0
Cash at end of year	0	0	0
Parent Company [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	(307,982)	(45,215)	(31,271)
Net cash provided by (used in) investing activities	33	(324,724)	(546,715)
Net cash provided by (used in) financing activities	208,440	469,654	577,973
Decrease in cash	(99,509)	99,715	(13)
Cash at beginning of year	99,795	80	93
Cash at end of year	286	99,795	80
Non-Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	21,308	6,694	13,916
Net cash provided by (used in) investing activities	(119,922)	(64,683)	(31,101)
Net cash provided by (used in) financing activities	96,307	60,110	17,353
Decrease in cash	(2,307)	2,121	168
Cash at beginning of year	2,307	186	18
Cash at end of year	0	2,307	186
Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	585,799	172,607	225,890
Net cash provided by (used in) investing activities	(597,519)	(401,034)	(410,843)
Net cash provided by (used in) financing activities	(2,843)	322,743	193,123
Decrease in cash	(14,563)	94,316	8,170
Cash at beginning of year	110,782	16,466	8,296
Cash at end of year	$ 96,219	$ 110,782	$ 16,466

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
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6676-107765

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 4
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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