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v3.3.1.900

Borrowings (Textual) (Details) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2015 USD ($) Contract instrument | Dec. 31, 2014 USD ($) | Dec. 31, 2013 USD ($) | Jun. 10, 2014
Debt Instrument [Line Items] |  |  |  |  |
Notes Payable |  | $ 3,427,568,000 | $ 3,512,700,000 |  |
Average interest rate (percentage) |  | 3.70% | 3.70% |  |
Interest Rate Swap |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Periodic Payment, Interest |  | $ 200,000,000 |  |  |
Interest rate, stated percentage |  | 4.17% |  |  |
Fixed Rate Debt |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Notes Payable |  | $ 3,148,100,000 | $ 3,074,700,000 |  |
Conventional Variable Rate Debt |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Long-term debt |  | $ 65,000,000 |  |  |
Variable interest rate (percent) |  | 0.80% |  |  |
Floating Rate Debt |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Notes Payable |  | $ 265,000,000 | 397,900,000 |  |
Capped Conventional Variable Rate Debt |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Long-term debt |  | $ 125,000,000 |  |  |
Variable interest rate (percent) |  | 0.80% |  |  |
Other Than Conventional Variable Rate Debt |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Long-term debt |  | $ 1,100,000,000 |  |  |
Average interest rates (percent) |  | 4.00% |  |  |
Fixed Rate Senior Notes |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Unsecured debt |  | $ 2,100,000,000 |  |  |
Long-term debt fixed interest rate (percent) |  | 3.90% |  |  |
Unsecured Debt |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Notes Payable |  | $ 2,141,332,000 |  |  |
Average interest rate (percentage) |  | 3.80% |  |  |
Unsecured Debt | 4.0% Senior Notes due 2025 [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt instrument, unamortized discount |  | $ 4,000,000 |  |  |
Underwriting commissions and expenses |  | 2,600,000 |  |  |
Proceeds from Unsecured Notes Payable |  | $ 393,400,000 |  |  |
Interest rate, stated percentage |  | 4.00% |  |  |
Debt Instrument, Issue Price |  | $ 0.9899 |  |  |
Debt Instrument, Face Amount |  | $ 400,000,000 |  |  |
Covenant Obligation, Debt to Total Asset Value |  | 60.00% |  |  |
Covenant obligation, Secured Debt to Total Asset Value Ratio |  | 40.00% |  |  |
Covenant Obligation, Unencumbered Leverage Ratio |  | 150.00% |  |  |
Unsecured Debt | $750 million unsecured revolving credit facility [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Average interest rate (percentage) |  | 1.23% |  |  |
Line of credit facility, maximum borrowing capacity |  | $ 750,000,000 |  |  |
Line of credit facility, amount outstanding |  | 75,000,000 |  |  |
Unsecured Debt | $500 million unsecured revolving credit faciltiy [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Line of Credit Facility, Current Borrowing Capacity |  | 746,700,000 |  |  |
Credit facilities, commitment fees |  | 1,100,000 |  |  |
Letters of credit outstanding amount |  | 3,300,000 |  |  |
Unsecured Debt | Fixed Rate Debt |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Notes Payable |  | $ 1,535,200,000 | 1,320,200,000 |  |
Average interest rates (percent) |  | 4.21% |  |  |
Unsecured Debt | Floating Rate Debt |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Notes Payable | [1] | $ 75,000,000 | 59,000,000 |  |
Average interest rates (percent) | [1] | 1.23% |  |  |
Interest rate, stated percentage | [1] | 1.23% |  |  |
Unsecured Debt | KeyBank Term Loan [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Face Amount |  | $ 150,000,000 |  |  |
Unsecured Debt | Wells Fargo Term Loan [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Face Amount |  | 250,000,000 |  |  |
Unsecured Debt | US Bank Term Loan [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Face Amount |  | $ 150,000,000 |  |  |
Unsecured Debt | Term Loan [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Average interest rate (percentage) |  | 3.10% |  |  |
Debt Instrument, Face Amount |  | $ 550,000,000 |  |  |
Unsecured Debt | 3.75% Seinor Notes due 2024 [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Covenant Obligation, Debt to Total Asset Value |  |  |  |  | 60.00%
Covenant obligation, Secured Debt to Total Asset Value Ratio |  |  |  |  | 40.00%
Covenant Obligation, Unencumbered Leverage Ratio |  |  |  |  | 150.00%
Unsecured Debt | 2011 and 2012 Senior Notes [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Face Amount |  | $ 310,000,000 |  |  |
Unsecured Debt | Minimum | $750 million unsecured revolving credit facility [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 0.85% |  |  |
Unsecured Debt | Minimum | KeyBank Term Loan [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 0.90% |  |  |
Unsecured Debt | Minimum | Wells Fargo Term Loan [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 0.90% |  |  |
Unsecured Debt | Minimum | 3.75% Seinor Notes due 2024 [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Covenant obligation, Fixed Charge Ratio |  |  |  |  | 100.00%
Unsecured Debt | Maximum | 4.0% Senior Notes due 2025 [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Covenant obligation, Fixed Charge Ratio |  | 150.00% |  |  |
Unsecured Debt | Maximum | $750 million unsecured revolving credit facility [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  | $ 1,500,000,000 |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 1.55% |  |  |
Unsecured Debt | Maximum | KeyBank Term Loan [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 1.75% |  |  |
Unsecured Debt | Maximum | Wells Fargo Term Loan [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 1.90% |  |  |
Unsecured Debt | Maximum | 3.75% Seinor Notes due 2024 [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Covenant obligation, Fixed Charge Ratio |  |  |  |  | 150.00%
Unsecured Debt | Variable Rate Debt | $500 million unsecured revolving credit faciltiy [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Average interest rate (percentage) |  | 1.20% |  |  |
Line of credit facility, amount outstanding |  | $ 75,000,000 |  |  |
Unsecured Debt | Fixed Rate Debt | Senior Notes |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Average interest rate (percentage) |  | 4.20% |  |  |
Debt Instrument, Face Amount |  | $ 1,535,246,000 |  |  |
Unsecured Debt | Fixed Rate Debt | Public Income Notes [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Face Amount |  | 1,200,000,000 |  |  |
Unsecured Debt | Fixed Rate Debt | Private Placement [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Face Amount |  | $ 0 |  |  |
Secured Debt [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Average interest rate (percentage) |  | 3.50% |  |  |
Secured Debt [Member] | FNMA |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  | $ 240,000,000 |  |  |
Line of credit facility, amount outstanding |  | 240,000,000 |  |  |
Line of Credit Facility, Current Borrowing Capacity |  | $ 240,000,000 |  |  |
Debt renewal period (days) |  | 90 days |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 0.17% |  |  |
Secured credit facilities, commitment fee percentage (percent) |  | 0.62% |  |  |
Credit facilities, commitment fees |  | $ 100,000 |  |  |
Secured Debt [Member] | Fixed Rate Debt |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Notes Payable |  | $ 1,062,862,000 |  |  |
Average interest rate (percentage) |  | 3.90% |  |  |
Secured Debt [Member] | Floating Rate Debt |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Notes Payable | [2] | $ 190,000,000 |  |  |
Average interest rate (percentage) |  | 0.80% |  |  |
Secured Debt [Member] | Variable Rate Debt | FNMA |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Average interest rate (percentage) |  | 0.80% |  |  |
Line of credit facility, amount outstanding |  | $ 190,000,000 |  |  |
Secured Debt [Member] | Variable Rate Debt | Mortgages |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Gains (Losses) on Extinguishment of Debt |  | $ 200,000 |  |  |
Secured Debt [Member] | Fixed Rate Debt | FNMA |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Average interest rate (percentage) |  | 4.70% |  |  |
Line of credit facility, amount outstanding |  | $ 50,000,000 |  |  |
Secured Debt [Member] | Fixed Rate Debt | Mortgages |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Average interest rate (percentage) |  | 3.90% |  |  |
Mortgage Loans on Real Estate |  | $ 1,012,862,000 |  |  |
Interest Rate Cap | Secured Debt [Member] | FNMA |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Number of Interest rate derivatives held (contracts) | Contract |  | 5 |  |  |
Derivative, Notional Amount |  | $ 125,000,000 |  |  |
Limited Partner [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Unsecured debt |  | 2,141,332,000 | 1,923,058,000 |  |
Proceeds from notes payable |  | 395,960,000 | 396,855,000 | $ 347,759,000 |
Gains (Losses) on Extinguishment of Debt |  | $ (3,602,000) | $ (2,586,000) | $ (426,000) |
Scenario 1 [Member] | Interest Rate Cap | Secured Debt [Member] | FNMA |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Number of Interest rate derivatives held (contracts) | instrument |  | 4 |  |  |
Derivative cap interest rate (percent) |  | 4.50% |  |  |
Scenario 2 [Member] | Interest Rate Cap | Secured Debt [Member] | FNMA |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Number of Interest rate derivatives held (contracts) | instrument |  | 1 |  |  |
Derivative cap interest rate (percent) |  | 5.00% |  |  |
[1] | Amounts are adjusted to reflect interest rate swap and cap agreements in effect at December 31, 2015, and 2014, respectively, which results in the Company paying fixed interest payments over the terms of the interest rate swaps and on changes in interest rates above the strike rate of the cap.
[2] | Includes capped balances

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- Definition Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399 + Details
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- Definition Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629 + Details
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- Definition Fees and commissions from underwriting securities, private placements of securities, investment advisory and management services, merger and acquisition services, and other related consulting fees. Include fees and commissions from securities brokerage activities, from the sale and servicing of mutual funds, from the purchase and sale of securities and money market instruments where the bank is acting as agent for other banks or customers, and from the lending of securities owned by the bank or by bank customers (exclusive of trading revenue). Also includes the bank's proportionate share of the income or loss before extraordinary items and other adjustments from its investments in: unconsolidated subsidiaries, associated companies and corporate joint ventures, unincorporated joint ventures, general partnerships, and limited partnerships over which the bank exercises significant influence and that are principally engaged in investment banking, advisory, brokerage, or securities underwriting activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.13(b)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 + Details
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5 + Details
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- Definition Amount of the fee for available but unused credit capacity under the credit facility. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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